java导出txt文本

页面

项目结构

html代码

<html>
</head>
  
  <body>
    <form action="down/downLoad" method="post">
    	<input type="text" name="name">
    	<input type="submit" value="Submit" />
    </form>
  </body>
</html>

注意form表单路径，也可以用request.getContextPath()/down/downLoad

web.xml　

<?xml version="1.0" encoding="UTF-8"?>
<web-app>
  
    <display-name>Spring MVC Application</display-name>
  
    <servlet>
		<servlet-name>mvc-dispatcher</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>
  
    <servlet-mapping>
		<servlet-name>mvc-dispatcher</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>
  
    <context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath*:mvc-dispatcher-servlet.xml</param-value>
	</context-param>
  
    <listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>
</web-app>

spring配置

<?xml version="1.0" encoding="UTF-8"?>  
<beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
    xmlns:context="http://www.springframework.org/schema/context"  
    xmlns:mvc="http://www.springframework.org/schema/mvc"  
    xmlns:p="http://www.springframework.org/schema/p"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans  
    http://www.springframework.org/schema/beans/spring-beans.xsd  
    http://www.springframework.org/schema/mvc  
    http://www.springframework.org/schema/mvc/spring-mvc.xsd  
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context.xsd"  >  
    
  <context:component-scan base-package="main.*" />
	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix"><value>/WEB-INF/pages</value></property>
		<property name="suffix"><value>.jsp</value></property>
	</bean>
	<bean id="dataSource"   class="org.springframework.jdbc.datasource.DriverManagerDataSource"
    p:driverClassName="com.mysql.jdbc.Driver"
    p:url="jdbc:mysql://localhost:3306/Student?useUnicode=true&characterEncoding=UTF-8"
    p:username="root"
    p:password="root" />
</beans>

　如果不从数据库查的话只用到controller就行了，List的数据自己构造

controller

package main.controller;

import java.io.BufferedOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import main.dao.GetInfoDao;
import main.model.Student;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/down")
public class DownLoadController {
	@Autowired
	private GetInfoDao dao;
	
	@RequestMapping("/downLoad")
	public void down(HttpServletRequest request,
            HttpServletResponse response){
		String name=request.getParameter("name");
		System.out.println("name:"+name);
		//List<Student> students=dao.getInfo();
		List<String> students = new ArrayList<String>(); 
		students.add("111111");
		students.add("222222");
		students.add("333333");
		students.add("444444");
		students.add("555555");
		//List<Student> students={};
		exportText(response, students);
	}
	public void exportText(HttpServletResponse response,List students){
		response.setContentType("text/plain");// 一下两行关键的设置  
        response.addHeader("Content-Disposition","attachment;filename=20160629.txt");
        BufferedOutputStream buff = null;  
        StringBuffer write = new StringBuffer();  
        String tab = "  ";  
        String enter = "
";  
        ServletOutputStream outSTr = null;  
        try {
			outSTr = response.getOutputStream();
			buff = new BufferedOutputStream(outSTr);  
            for (Object li :students) {
            	write.append("名字：" + tab);  
                write.append(li + enter);  
                write.append(enter);   
            }
            buff.write(write.toString().getBytes("UTF-8"));  
            buff.flush();  
            buff.close(); 
		} catch (IOException e) {
			e.printStackTrace();
		}// 建立  
	}
}

结果，导出来的数据

用到数据库的话,把数据库的数据查询出来放到List集合即可

这时候需要更新spring配置，XML配置不需要更改

我这使用springJdbc操作

<?xml version="1.0" encoding="UTF-8"?>  
<beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
    xmlns:context="http://www.springframework.org/schema/context"  
    xmlns:mvc="http://www.springframework.org/schema/mvc"  
    xmlns:p="http://www.springframework.org/schema/p"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans  
    http://www.springframework.org/schema/beans/spring-beans.xsd  
    http://www.springframework.org/schema/mvc  
    http://www.springframework.org/schema/mvc/spring-mvc.xsd  
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context.xsd"  >  
    
  <context:component-scan base-package="main.*" />
	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix"><value>/WEB-INF/pages</value></property>
		<property name="suffix"><value>.jsp</value></property>
	</bean>
	<bean id="dataSource"   class="org.springframework.jdbc.datasource.DriverManagerDataSource"
    p:driverClassName="com.mysql.jdbc.Driver"
    p:url="jdbc:mysql://localhost:3306/Student?useUnicode=true&characterEncoding=UTF-8"
    p:username="root"
    p:password="root" />
     <!-- 定义jdbc模板的bean -->
 <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"
 p:dataSource-ref="dataSource" />
</beans>

Student:

package main.model;

import org.springframework.stereotype.Component;

@Component
public class Student {
	private int id;
	private String name;
	private int age;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
}

DAO:

package main.dao;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import main.model.Student;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Repository;

@Repository
public class GetInfoDao {
	@Autowired
	private JdbcTemplate template;
	
	public List<Student> getInfo(){
		String sql="select * from T_Student";
		List<Student> students=new ArrayList<Student>();
		students=template.query(sql, new StudentMapper());
		return students;
		
	}
	public class StudentMapper implements RowMapper<Student> {
		  public Student mapRow(ResultSet rs, int rowNum) throws SQLException {
		   Student student = new Student();
		   student.setId(rs.getInt("id"));
		   student.setName(rs.getString("name"));
		   student.setAge(rs.getInt("age"));
		   return student;
		  }
	}

}

Controller:　

package main.controller;

import java.io.BufferedOutputStream;
import java.io.IOException;
import java.util.List;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import main.dao.GetInfoDao;
import main.model.Student;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/down")
public class DownLoadController {
	@Autowired
	private GetInfoDao dao;
	
	@RequestMapping("/downLoad")
	public void down(HttpServletRequest request,
            HttpServletResponse response){
		String name=request.getParameter("name");
		System.out.println("name:"+name);
		List<Student> students=dao.getInfo();
		exportText(response, students);
	}
	public void exportText(HttpServletResponse response,List students){
		response.setContentType("text/plain");// 一下两行关键的设置  
        response.addHeader("Content-Disposition","attachment;filename=20160629.txt");
        BufferedOutputStream buff = null;  
        StringBuffer write = new StringBuffer();  
        String tab = "  ";  
        String enter = "
";  
        ServletOutputStream outSTr = null;  
        try {
			outSTr = response.getOutputStream();
			buff = new BufferedOutputStream(outSTr);  
			write.append("ID"+tab+"姓名"+tab+"年龄"+ enter);
            for (int i=0;i<students.size();i++) {
            	Student s=(Student)students.get(i);
            	write.append(s.getId()+ tab); 
                write.append(s.getName()+ tab); 
                write.append(s.getAge()+ enter); 
                write.append(enter);   
            }
            buff.write(write.toString().getBytes("UTF-8"));  
            buff.flush();  
            buff.close(); 
		} catch (IOException e) {
			e.printStackTrace();
		}// 建立  
	}
	public String delNull(String str){
		String xx="****";
		if (str!=null||!"".equals(str)){
			xx=str;
		}
		return xx;
		
	}

}

导出来的数据截图：

如果数据量大的话则采用先把数据写到一个文件里面，然后再去下载这个文件

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原文地址：https://www.cnblogs.com/JAYIT/p/5628883.html