• 实验五 网络编程与安全


    20165225 实验五 网络编程与安全


    实验报告封面:

    课程:Java程序设计  班级:1652班  姓名:王高源 学号:20165225
    
    指导教师:娄嘉鹏 实验日期:2018年5月14日
    
    实验时间:3:35 - 5:15 实验序号:实验5
    
    实验名称:网络编程与安全
    
    实验内容:
    
    1、掌握Java Socket的相关内容;
    2、学会建立客户端与服务器端之间的联系;
    3、学习并应用密码学的相关内容
    
    严禁抄袭,有该行为者实验成绩归零,并附加其他惩罚措施。
    

    网络编程与安全一:

    实验要求:

    两人一组结对编程:

    参考http://www.cnblogs.com/rocedu/p/6766748.html#SECDSA
    结对实现中缀表达式转后缀表达式的功能 MyBC.java
    结对实现从上面功能中获取的表达式中实现后缀表达式求值的功能,调用MyDC.java

    实验代码:

    Client

    import java.net.*;
    import java.io.*;
    public class Client
    {
        public static void main(String srgs[]) throws Exception
        {
            try
            {
                // 1、创建客户端Socket,指定服务器地址和端口
                Socket socket=new Socket("127.0.0.1",10000);
                System.out.println("客户端成功启动,等待服务器应答");
                // 2、获取输出流,向服务器端发送信息
                // 向本机的10001端口发出客户请求
                System.out.println("请输入中缀表达式:");
                BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
                // 由系统标准输入设备构造BufferedReader对象
                PrintWriter write = new PrintWriter(socket.getOutputStream());
                // 由Socket对象得到输出流,并构造PrintWriter对象
                //3、获取输入流,并读取服务器端的响应信息
                BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                // 由Socket对象得到输入流,并构造相应的BufferedReader对象
                String readline, infix, expression;
                readline = br.readLine(); // 从系统标准输入读入一字符串
                MyBC theTrans = new MyBC(readline);
                infix = theTrans.doTrans();
                StringBuilder newInfix = new StringBuilder(infix.replace(" ",""));
                for (int i = 1; i < infix.length()+(i+1)/2 ; i=i+2) {
                    newInfix.insert(i," ");
                }
                System.out.println("后缀表达式:" + newInfix);
                expression=newInfix.toString();
    
                while (!readline.equals("end")) {
                    // 若从标准输入读入的字符串为 "end"则停止循环
                    write.println(expression);
                    // 将从系统标准输入读入的字符串输出到Server
                    write.flush();
                    // 刷新输出流,使Server马上收到该字符串
                    System.out.println("收到服务器的消息:" + in.readLine());
                    // 从Server读入一字符串,并打印到标准输出上
                    readline = br.readLine(); // 从系统标准输入读入一字符串
                } // 继续循环
                //4、关闭资源
                write.close(); // 关闭Socket输出流
                in.close(); // 关闭Socket输入流
                socket.close(); // 关闭Socket
            }
            catch (Exception e)
            {
                System.out.println(e);//输出异常
            }
            finally
            {
    
            }
    
        }
    }
    

    Server

    import java.net.*;
    import java.io.*;
    
    public class Server{
        public static void main(String srgs[]) throws Exception
        {
            ServerSocket sc = null;
            Socket socket=null;
            try
            {
                MyDC evaluator = new MyDC();
    
                sc= new ServerSocket(10000);//创建服务器套接字
                System.out.println("端口号:" + sc.getLocalPort());
                System.out.println("服务器成功启动,等待客户端呼叫");
                socket = sc.accept();   //等待客户端连接
                System.out.println("已经建立连接");//获得网络输入流对象的引用
                BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));//获得网络输出流对象的引用
                PrintWriter out=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
                String aline2=in.readLine();
                System.out.println("客户端发来的信息为:"+aline2);
    
                int ans = evaluator.evaluate(aline2);
                out.println(ans);
                System.out.println("result = "+ans);
            } catch (Exception e) {
                System.out.println(e);
            }
        }
    
        //十六进制和十进制转换
        public static byte[] parseHexStr2Byte(String hexStr)
        {
            if (hexStr.length() < 1)
                return null;
            byte[] result = new byte[hexStr.length()/2];
            for (int i = 0;i< hexStr.length()/2; i++)
            {
                int high = Integer.parseInt(hexStr.substring(i*2, i*2+1 ), 16);
                int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16);
                result[i] = (byte) (high * 16 + low);
            }
            return result;
        }
    }
    
    

    MyDc

    import java.util.StringTokenizer;
    import java.util.Stack;
    
    public class MyDC {
        /**
         * constant for addition symbol
         */
        private final char ADD = '+';
        /**
         * constant for subtraction symbol
         */
        private final char SUBTRACT = '-';
        /**
         * constant for multiplication symbol
         */
        private final char MULTIPLY = '*';
        /**
         * constant for division symbol
         */
        private final char DIVIDE = '/';
        /**
         * the stack
         */
        private Stack<Integer> stack;
    
        public MyDC() {
            stack = new Stack<Integer>();
        }
    
        public int evaluate(String expr) {
            int op1, op2, result = 0;
            String token;
            StringTokenizer tokenizer = new StringTokenizer(expr);
            while (tokenizer.hasMoreTokens()) {
                token = tokenizer.nextToken();
    
                //如果是运算符,调用isOperator
                if (isOperator(token)) {
                    //从栈中弹出操作数2
                    op2 = stack.pop();
                    //从栈中弹出操作数1
                    op1 = stack.pop();
                    //根据运算符和两个操作数调用evalSingleOp计算result;
                    result=evalSingleOp(token.charAt(0), op1, op2);
                    //计算result入栈;
                    stack.push(result);
                } else//如果是操作数
                    //操作数入栈;
                    stack.push(Integer.parseInt(token));
            }
    
            return result;
        }
    
        private boolean isOperator(String token) {
            return (token.equals("+") || token.equals("-") ||
                    token.equals("*") || token.equals("/"));
        }
    
        private int evalSingleOp(char operation, int op1, int op2) {
            int result = 0;
    
            switch (operation) {
                case ADD:
                    result = op1 + op2;
                    break;
                case SUBTRACT:
                    result = op1 - op2;
                    break;
                case MULTIPLY:
                    result = op1 * op2;
                    break;
                case DIVIDE:
                    result = op1 / op2;
            }
    
            return result;
        }
    }
    

    MyBc

    public class MyBC {
        private Stack theStack;
        private String input;
        private String output = "";
        public MyBC(String in) {
            input = in;
            int stackSize = input.length();
            theStack = new Stack(stackSize);
        }
        public String doTrans() {
            for (int j = 0; j < input.length(); j++) {
                char ch = input.charAt(j);
                switch (ch) {
                    case '+':
                    case '-':
                        gotOper(ch, 1);
                        break;
                    case '*':
                    case '/':
                        gotOper(ch, 2);
                        break;
                    case '(':
                        theStack.push(ch);
                        break;
                    case ')':
                        gotParen(ch);
                        break;
                    default:
                        output = output + ch;
                        break;
                }
            }
            while (!theStack.isEmpty()) {
                output = output + theStack.pop();
            }
            return output;
        }
        public void gotOper(char opThis, int prec1) {
            while (!theStack.isEmpty()) {
                char opTop = theStack.pop();
                if (opTop == '(') {
                    theStack.push(opTop);
                    break;
                }
                else {
                    int prec2;
                    if (opTop == '+' || opTop == '-')
                        prec2 = 1;
                    else
                        prec2 = 2;
                    if (prec2 < prec1) {
                        theStack.push(opTop);
                        break;
                    }
                    else
                        output = output + opTop;
                }
            }
            theStack.push(opThis);
        }
        public void gotParen(char ch){
            while (!theStack.isEmpty()) {
                char chx = theStack.pop();
                if (chx == '(')
                    break;
                else
                    output = output + chx;
            }
        }
        class Stack {
            private int maxSize;
            private char[] stackArray;
            private int top;
            public Stack(int max) {
                maxSize = max;
                stackArray = new char[maxSize];
                top = -1;
            }
            public void push(char j) {
                stackArray[++top] = j;
            }
            public char pop() {
                return stackArray[top--];
            }
            public char peek() {
                return stackArray[top];
            }
            public boolean isEmpty() {
                return (top == -1);
            }
        }
    }
    

    实验截图:

    image

    image

    网络编程与安全二:

    结对编程:1人负责客户端,一人负责服务器

    注意责任归宿,要会通过测试证明自己没有问题
    基于Java Socket实现客户端/服务器功能,传输方式用TCP
    客户端让用户输入中缀表达式,然后把中缀表达式调用MyBC.java的功能转化为后缀表达式,把后缀表达式通过网络发送给服务器
    服务器接收到后缀表达式,调用MyDC.java的功能计算后缀表达式的值,把结果发送给客户端
    客户端显示服务器发送过来的结果

    实验代码:

    Server

    import javax.crypto.Cipher;
    import javax.crypto.spec.SecretKeySpec;
    import java.io.DataInputStream;
    import java.io.DataOutputStream;
    import java.io.FileInputStream;
    import java.io.IOException;
    import java.net.ServerSocket;
    import java.net.Socket;
    public class Server1 {
        public static void main(String args[]) {
            ServerSocket serverForClient = null;
            Socket socketOnServer = null;
            DataOutputStream out = null;
            DataInputStream in = null;
            try {
                serverForClient = new ServerSocket(3001);
            } catch (IOException e1) {
                System.out.println(e1);
            }
            try {
                System.out.println("等待客户呼叫");
                socketOnServer = serverForClient.accept(); //堵塞状态,除非有客户呼叫
                System.out.println("客户已连接");
                out = new DataOutputStream(socketOnServer.getOutputStream());
                in = new DataInputStream(socketOnServer.getInputStream());
                String leng = in.readUTF(); // in读取信息,堵塞状态
                byte ctext[] = new byte[Integer.parseInt(leng)];
                for (int i = 0;i<Integer.parseInt(leng);i++) {
                    String temp = in.readUTF();
                    ctext[i] = Byte.parseByte(temp);
                }
                // 获取密钥
                FileInputStream f2 = new FileInputStream("keykb1.txt");
                int num2 = f2.available();
                byte[] keykb = new byte[num2];
                f2.read(keykb);
                SecretKeySpec k = new SecretKeySpec(keykb, "DESede");
                // 解密
                Cipher cp = Cipher.getInstance("DESede");
                cp.init(Cipher.DECRYPT_MODE, k);
                byte[] ptext = cp.doFinal(ctext);
                System.out.println("后缀表达式已被解密:");
                for (int i = 0; i < ptext.length; i++) {
                    System.out.print(ptext[i] + ",");
                }
                System.out.println("");
                // 显示明文
                String p = new String(ptext, "UTF8");
                System.out.println("服务器收到客户的请求:计算后缀表达式" + p);
                MyDC evaluator = new MyDC();
                out.writeUTF(evaluator.evaluate(p)+"");
            } catch (Exception e) {
                System.out.println("客户已断开" + e);
            }
        }
    }
    

    Client

    
    

    实验截图:

    image

    网络编程与安全三:

    加密结对编程:1人负责客户端,一人负责服务器

    注意责任归宿,要会通过测试证明自己没有问题
    基于Java Socket实现客户端/服务器功能,传输方式用TCP
    客户端让用户输入中缀表达式,然后把中缀表达式调用MyBC.java的功能转化为后缀表达式,把后缀表达式用3DES或AES算法加密后通过网络把密文发送给服务器
    服务器接收到后缀表达式表达式后,进行解密(和客户端协商密钥,可以用数组保存),然后调用MyDC.java的功能计算后缀表达式的值,把结果发送给客户端
    客户端显示服务器发送过来的结果

    实验代码:

    Server

    import javax.crypto.Cipher;
    import javax.crypto.SecretKey;
    import javax.crypto.spec.SecretKeySpec;
    import java.io.*;
    import java.net.ServerSocket;
    import java.net.Socket;
    import java.security.Key;
    import java.util.Optional;
    
    public class Server2 {
        public static void main(String args[]) {
            ServerSocket serverForClient = null;
            Socket socketOnServer = null;
            DataOutputStream out = null;
            DataInputStream in = null;
            try {
                serverForClient = new ServerSocket(2010);
            } catch (IOException e1) {
                System.out.println(e1);
            }
            try {
                System.out.println("等待客户呼叫");
                socketOnServer = serverForClient.accept(); //堵塞状态,除非有客户呼叫
                System.out.println("客户已连接");
                out = new DataOutputStream(socketOnServer.getOutputStream());
                in = new DataInputStream(socketOnServer.getInputStream());
    
                Key_DH.fun("Spub.txt","Spri.txt");
                int len = Integer.parseInt(in.readUTF());
                byte np[] = new byte[len];
                for (int i = 0;i<len;i++) {
                    String temp = in.readUTF();
                    np[i] = Byte.parseByte(temp);
                }
                ObjectInputStream ois = new ObjectInputStream (new ByteArrayInputStream (np));
                Key k2 = (Key)ois.readObject();;
                FileOutputStream f2 = new FileOutputStream("Cpub.txt");
                ObjectOutputStream b2 = new ObjectOutputStream(f2);
                b2.writeObject(k2);
    
                FileInputStream fp = new FileInputStream("Spub.txt");
                ObjectInputStream bp = new ObjectInputStream(fp);
                Key kp = (Key) bp.readObject();
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                ObjectOutputStream oos = new ObjectOutputStream(baos);
                oos.writeObject(kp);
                byte[] kb = baos.toByteArray();
                out.writeUTF(kb.length + "");
                for (int i = 0; i < kb.length; i++) {
                    out.writeUTF(kb[i] + "");
                }
    
                KeyAgree.fun("Cpub.txt","Spri.txt");
    
                String leng = in.readUTF(); // in读取信息,堵塞状态
                byte ctext[] = new byte[Integer.parseInt(leng)];
                for (int i = 0;i<Integer.parseInt(leng);i++) {
                    String temp = in.readUTF();
                    ctext[i] = Byte.parseByte(temp);
                }
                // 获取密钥
                FileInputStream f = new FileInputStream("sb.txt");
                byte[] keysb = new byte[24];
                f.read(keysb);
                System.out.println("公共密钥:");
                for (int i = 0;i<24;i++) {
                    System.out.print(keysb[i]+",");
                }
                System.out.println("");
                SecretKeySpec k = new SecretKeySpec(keysb, "DESede");
                // 解密
                Cipher cp = Cipher.getInstance("DESede");
                cp.init(Cipher.DECRYPT_MODE, k);
                byte[] ptext = cp.doFinal(ctext);
                System.out.println("后缀表达式已被解密:");
                for (int i = 0; i < ptext.length; i++) {
                    System.out.print(ptext[i] + ",");
                }
                System.out.println("");
                // 显示明文
                String p = new String(ptext, "UTF8");
                System.out.println("服务器收到客户的请求:计算后缀表达式" + p);
                MyDC evaluator = new MyDC();
                out.writeUTF(evaluator.evaluate(p)+"");
            } catch (Exception e) {
                System.out.println("客户已断开" + e);
            }
        }
    }
    

    实验编程:

    网络编程与安全四:

    密钥分发结对编程:1人负责客户端,一人负责服务器

    注意责任归宿,要会通过测试证明自己没有问题
    基于Java Socket实现客户端/服务器功能,传输方式用TCP
    客户端让用户输入中缀表达式,然后把中缀表达式调用MyBC.java的功能转化为后缀表达式,把后缀表达式用3DES或AES算法加密通过网络把密文发送给服务器
    客户端和服务器用DH算法进行3DES或AES算法的密钥交换
    服务器接收到后缀表达式表达式后,进行解密,然后调用MyDC.java的功能计算后缀表达式的值,把结果发送给客户端
    客户端显示服务器发送过来的结果

    实验代码:

    server

    import javax.crypto.Cipher;
    import javax.crypto.spec.SecretKeySpec;
    import java.io.*;
    import java.net.ServerSocket;
    import java.net.Socket;
    import java.security.Key;
    
    public class Server3 {
        public static void main(String args[]) {
            ServerSocket serverForClient = null;
            Socket socketOnServer = null;
            DataOutputStream out = null;
            DataInputStream in = null;
            try {
                serverForClient = new ServerSocket(3001);
            } catch (IOException e1) {
                System.out.println(e1);
            }
            try {
                System.out.println("等待客户呼叫");
                socketOnServer = serverForClient.accept(); //堵塞状态,除非有客户呼叫
                System.out.println("客户已连接");
                out = new DataOutputStream(socketOnServer.getOutputStream());
                in = new DataInputStream(socketOnServer.getInputStream());
    
                Key_DH.fun("Spub.txt","Spri.txt");
                int len = Integer.parseInt(in.readUTF());
                byte np[] = new byte[len];
                for (int i = 0;i<len;i++) {
                    String temp = in.readUTF();
                    np[i] = Byte.parseByte(temp);
                }
                ObjectInputStream ois = new ObjectInputStream (new ByteArrayInputStream(np));
                Key k2 = (Key)ois.readObject();;
                FileOutputStream f2 = new FileOutputStream("Cpub.txt");
                ObjectOutputStream b2 = new ObjectOutputStream(f2);
                b2.writeObject(k2);
    
                FileInputStream fp = new FileInputStream("Spub.txt");
                ObjectInputStream bp = new ObjectInputStream(fp);
                Key kp = (Key) bp.readObject();
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                ObjectOutputStream oos = new ObjectOutputStream(baos);
                oos.writeObject(kp);
                byte[] kb = baos.toByteArray();
                out.writeUTF(kb.length + "");
                for (int i = 0; i < kb.length; i++) {
                    out.writeUTF(kb[i] + "");
                }
    
                KeyAgree.fun("Cpub.txt","Spri.txt");
    
                String leng = in.readUTF(); // in读取信息,堵塞状态
                byte ctext[] = new byte[Integer.parseInt(leng)];
                for (int i = 0;i<Integer.parseInt(leng);i++) {
                    String temp = in.readUTF();
                    ctext[i] = Byte.parseByte(temp);
                }
                String check = in.readUTF();
                // 获取密钥
                FileInputStream f = new FileInputStream("sb.txt");
                byte[] keysb = new byte[24];
                f.read(keysb);
                System.out.println("公共密钥:");
                for (int i = 0;i<24;i++) {
                    System.out.print(keysb[i]+",");
                }
                System.out.println("");
                SecretKeySpec k = new SecretKeySpec(keysb, "DESede");
                // 解密
                Cipher cp = Cipher.getInstance("DESede");
                cp.init(Cipher.DECRYPT_MODE, k);
                byte[] ptext = cp.doFinal(ctext);
                System.out.println("后缀表达式已被解密:");
                for (int i = 0; i < ptext.length; i++) {
                    System.out.print(ptext[i] + ",");
                }
                System.out.println("");
                // 显示明文
                String p = new String(ptext, "UTF8");
                String pMd5 = DigestPass.fun(p);
                System.out.println("解密后明文的MD5值:"+pMd5);
                if (pMd5.equals(check)){
                    System.out.println("和客户端的MD5值一致");
                    System.out.println("服务器收到客户的请求:计算后缀表达式" + p);
                    MyDC evaluator = new MyDC();
                    out.writeUTF(evaluator.evaluate(p)+"");
                }
                else {
                    System.out.println("警告:和客户端的MD5值不一致!");
                }
            } catch (Exception e) {
                System.out.println("客户已断开" + e);
            }
        }
    }
    

    实验截图:

    image

    网络编程与安全五:

    完整性校验结对编程:1人负责客户端,一人负责服务器

    注意责任归宿,要会通过测试证明自己没有问题
    基于Java Socket实现客户端/服务器功能,传输方式用TCP
    客户端让用户输入中缀表达式,然后把中缀表达式调用MyBC.java的功能转化为后缀表达式,把后缀表达式用3DES或AES算法加密通过网络把密文和明文的MD5値发送给服务器
    客户端和服务器用DH算法进行3DES或AES算法的密钥交换
    服务器接收到后缀表达式表达式后,进行解密,解密后计算明文的MD5值,和客户端传来的MD5进行比较,一致则调用MyDC.java的功能计算后缀表达式的值,把结果发送给客户端
    客户端显示服务器发送过来的结果

    实验代码:

    Client

    import java.net.*;
    import java.io.*;
    public class Client
    {
        public static void main(String srgs[]) throws Exception
        {
            try
            {
                // 1、创建客户端Socket,指定服务器地址和端口
                Socket socket=new Socket("127.0.0.1",10000);
                System.out.println("客户端成功启动,等待服务器应答");
                // 2、获取输出流,向服务器端发送信息
                // 向本机的10001端口发出客户请求
                System.out.println("请输入中缀表达式:");
                BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
                // 由系统标准输入设备构造BufferedReader对象
                PrintWriter write = new PrintWriter(socket.getOutputStream());
                // 由Socket对象得到输出流,并构造PrintWriter对象
                //3、获取输入流,并读取服务器端的响应信息
                BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                // 由Socket对象得到输入流,并构造相应的BufferedReader对象
                String readline, infix, expression;
                readline = br.readLine(); // 从系统标准输入读入一字符串
                MyBC theTrans = new MyBC(readline);
                infix = theTrans.doTrans();
                StringBuilder newInfix = new StringBuilder(infix.replace(" ",""));
                for (int i = 1; i < infix.length()+(i+1)/2 ; i=i+2) {
                    newInfix.insert(i," ");
                }
                System.out.println("后缀表达式:" + newInfix);
                expression=newInfix.toString();
    
                while (!readline.equals("end")) {
                    // 若从标准输入读入的字符串为 "end"则停止循环
                    write.println(expression);
                    // 将从系统标准输入读入的字符串输出到Server
                    write.flush();
                    // 刷新输出流,使Server马上收到该字符串
                    System.out.println("收到服务器的消息:" + in.readLine());
                    // 从Server读入一字符串,并打印到标准输出上
                    readline = br.readLine(); // 从系统标准输入读入一字符串
                } // 继续循环
                //4、关闭资源
                write.close(); // 关闭Socket输出流
                in.close(); // 关闭Socket输入流
                socket.close(); // 关闭Socket
            }
            catch (Exception e)
            {
                System.out.println(e);//输出异常
            }
            finally
            {
    
            }
    
        }
    }import java.net.*;
    import java.io.*;
    public class Client
    {
        public static void main(String srgs[]) throws Exception
        {
            try
            {
                // 1、创建客户端Socket,指定服务器地址和端口
                Socket socket=new Socket("127.0.0.1",10000);
                System.out.println("客户端成功启动,等待服务器应答");
                // 2、获取输出流,向服务器端发送信息
                // 向本机的10001端口发出客户请求
                System.out.println("请输入中缀表达式:");
                BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
                // 由系统标准输入设备构造BufferedReader对象
                PrintWriter write = new PrintWriter(socket.getOutputStream());
                // 由Socket对象得到输出流,并构造PrintWriter对象
                //3、获取输入流,并读取服务器端的响应信息
                BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                // 由Socket对象得到输入流,并构造相应的BufferedReader对象
                String readline, infix, expression;
                readline = br.readLine(); // 从系统标准输入读入一字符串
                MyBC theTrans = new MyBC(readline);
                infix = theTrans.doTrans();
                StringBuilder newInfix = new StringBuilder(infix.replace(" ",""));
                for (int i = 1; i < infix.length()+(i+1)/2 ; i=i+2) {
                    newInfix.insert(i," ");
                }
                System.out.println("后缀表达式:" + newInfix);
                expression=newInfix.toString();
    
                while (!readline.equals("end")) {
                    // 若从标准输入读入的字符串为 "end"则停止循环
                    write.println(expression);
                    // 将从系统标准输入读入的字符串输出到Server
                    write.flush();
                    // 刷新输出流,使Server马上收到该字符串
                    System.out.println("收到服务器的消息:" + in.readLine());
                    // 从Server读入一字符串,并打印到标准输出上
                    readline = br.readLine(); // 从系统标准输入读入一字符串
                } // 继续循环
                //4、关闭资源
                write.close(); // 关闭Socket输出流
                in.close(); // 关闭Socket输入流
                socket.close(); // 关闭Socket
            }
            catch (Exception e)
            {
                System.out.println(e);//输出异常
            }
            finally
            {
    
            }
    
        }
    }
    

    实验截图:

    image

    image

    PSP(Personal Software Process)时间:

    步骤 耗时 百分比
    功能实现 55min 12.5%
    测试 25min 15.6%
    分析总结 20min 12.5%
  • 相关阅读:
    MATLAB仿真学习笔记(一)
    SolidWorks学习笔记(一)
    机械制造技术学习笔记(七)
    基于MATLAB的多功能语音处理器
    MATLAB图形界面设计(下)
    36、如何避免僵尸进程?
    37、局部性原理你知道吗?主要有哪两大局部性原理?各自是什么?
    35、 守护进程、僵尸进程和孤儿进程
    32、什么是快表,你知道多少关于快表的知识?
    30、终端退出,终端运行的进程会怎样?31、如何让进程后台运行
  • 原文地址:https://www.cnblogs.com/nmsl123/p/9131018.html
Copyright © 2020-2023  润新知