Java常用工具类---image图片处理工具类、Json工具类

package com.jarvis.base.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import net.coobird.thumbnailator.Thumbnails;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

/**
 *   
 * 
 * @Title: ImageHelper.java
 * @Package com.jarvis.base.util
 * @Description:图片处理工具类。
 * @version V1.0  
 */
@SuppressWarnings("restriction")
public class ImageHelper {
	/**
	 * @描述：Base64解码并生成图片
	 * @入参：@param imgStr
	 * @入参：@param imgFile
	 * @入参：@throws IOException
	 * @出参：void
	 */
	public static void generateImage(String imgStr, String imgFile) throws IOException {
		BASE64Decoder decoder = new BASE64Decoder();
		// Base64解码
		byte[] bytes;
		OutputStream out = null;
		try {
			bytes = decoder.decodeBuffer(imgStr);
			for (int i = 0; i < bytes.length; ++i) {
				if (bytes[i] < 0) {// 调整异常数据
					bytes[i] += 256;
				}
			}
			// 生成图片
			out = new FileOutputStream(imgFile);
			out.write(bytes);
			out.flush();
		} catch (IOException e) {
			throw new IOException();
		} finally {
			if (out != null) {
				try {
					out.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}

	}

	/**
	 * @throws IOException
	 * @描述：根据路径得到base编码后图片
	 * @入参：@param imgFilePath
	 * @入参：@return
	 * @出参：String
	 */
	public static String getImageStr(String imgFilePath) throws IOException {// 将图片文件转化为字节数组字符串，并对其进行Base64编码处理
		byte[] data = null;

		// 读取图片字节数组
		try {
			InputStream in = new FileInputStream(imgFilePath);
			data = new byte[in.available()];
			in.read(data);
			in.close();
		} catch (IOException e) {
			throw new IOException();
		}

		// 对字节数组Base64编码
		BASE64Encoder encoder = new BASE64Encoder();
		return encoder.encode(data);// 返回Base64编码过的字节数组字符串
	}

	/**
	 * @throws IOException
	 * @描述：图片旋转
	 * @入参：@param base64In 传入的图片base64
	 * @入参：@param angle 图片旋转度数
	 * @入参：@throws Exception
	 * @出参：String 传出的图片base64
	 */
	public static String imgAngleRevolve(String base64In, int angle) throws IOException {
		ByteArrayOutputStream os = new ByteArrayOutputStream();
		try {
			Thumbnails.of(base64ToIo(base64In)).scale(1.0).rotate(angle).toOutputStream(os);
		} catch (IOException e) {
			throw new IOException();
		}
		byte[] bs = os.toByteArray();
		String s = new BASE64Encoder().encode(bs);
		return s;
	}

	/**
	 * @描述：base64转为io流
	 * @入参：@param strBase64
	 * @入参：@return
	 * @入参：@throws IOException
	 * @出参：InputStream
	 */
	public static InputStream base64ToIo(String strBase64) throws IOException {
		// 解码，然后将字节转换为文件
		byte[] bytes = new BASE64Decoder().decodeBuffer(strBase64); // 将字符串转换为byte数组
		return new ByteArrayInputStream(bytes);
	}
}







package com.jarvis.base.util;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.List;
import java.util.Map;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.TypeReference;
import com.alibaba.fastjson.serializer.JSONLibDataFormatSerializer;
import com.alibaba.fastjson.serializer.SerializeConfig;
import com.alibaba.fastjson.serializer.SerializerFeature;

/**
 *   
 * 
 * @Title: FastJsonUtil.java
 * @Package com.jarvis.base.util
 * @Description:fastjson工具类
 * @version V1.0  
 */
public class FastJsonUtil {

	private static final SerializeConfig config;

	static {
		config = new SerializeConfig();
		config.put(java.util.Date.class, new JSONLibDataFormatSerializer()); // 使用和json-lib兼容的日期输出格式
		config.put(java.sql.Date.class, new JSONLibDataFormatSerializer()); // 使用和json-lib兼容的日期输出格式
	}

	private static final SerializerFeature[] features = { SerializerFeature.WriteMapNullValue, // 输出空置字段
			SerializerFeature.WriteNullListAsEmpty, // list字段如果为null，输出为[]，而不是null
			SerializerFeature.WriteNullNumberAsZero, // 数值字段如果为null，输出为0，而不是null
			SerializerFeature.WriteNullBooleanAsFalse, // Boolean字段如果为null，输出为false，而不是null
			SerializerFeature.WriteNullStringAsEmpty, // 字符类型字段如果为null，输出为""，而不是null
			SerializerFeature.PrettyFormat  //是否需要格式化输出Json数据
	};

	/**
	 * @param object
	 * @return Return:String Description:将对象转成成Json对象
	 */
	public static String toJSONString(Object object) {
		return JSON.toJSONString(object, config, features);
	}

	/**
	 * @param object
	 * @return Return:String Description:使用和json-lib兼容的日期输出格式
	 */
	public static String toJSONNoFeatures(Object object) {
		return JSON.toJSONString(object, config);
	}

	/**
	 * @param jsonStr
	 * @return Return:Object Description:将Json数据转换成JSONObject
	 */
	public static JSONObject toJsonObj(String jsonStr) {
		return (JSONObject) JSON.parse(jsonStr);
	}
	
	/**
	 * @param jsonStr
	 * @param clazz
	 * @return Return:T Description:将Json数据转换成Object
	 */
	public static <T> T toBean(String jsonStr, Class<T> clazz) {
		return JSON.parseObject(jsonStr, clazz);
	}

	/**
	 * @param jsonStr
	 * @return Return:Object[] Description:将Json数据转换为数组
	 */
	public static <T> Object[] toArray(String jsonStr) {
		return toArray(jsonStr, null);
	}

	/**
	 * @param jsonStr
	 * @param clazz
	 * @return Return:Object[] Description:将Json数据转换为数组
	 */
	public static <T> Object[] toArray(String jsonStr, Class<T> clazz) {
		return JSON.parseArray(jsonStr, clazz).toArray();
	}

	/**
	 * @param jsonStr
	 * @param clazz
	 * @return Return:List<T> Description:将Json数据转换为List
	 */
	public static <T> List<T> toList(String jsonStr, Class<T> clazz) {
		return JSON.parseArray(jsonStr, clazz);
	}

	/**
	 * 将javabean转化为序列化的JSONObject对象
	 * 
	 * @param keyvalue
	 * @return
	 */
	public static JSONObject beanToJsonObj(Object bean) {
		String jsonStr = JSON.toJSONString(bean);
		JSONObject objectJson = (JSONObject) JSON.parse(jsonStr);
		return objectJson;
	}
	/**
	 * json字符串转化为map
	 * 
	 * @param s
	 * @return
	 */
	public static Map<?, ?> stringToCollect(String jsonStr) {
		Map<?, ?> map = JSONObject.parseObject(jsonStr);
		return map;
	}

	/**
	 * 将map转化为string
	 * 
	 * @param m
	 * @return
	 */
	public static String collectToString(Map<?, ?> map) {
		String jsonStr = JSONObject.toJSONString(map);
		return jsonStr;
	}

	/**
	 * @param t
	 * @param file
	 * @throws IOException
	 *             Return:void Description:将对象的Json数据写入文件。
	 */
	public static <T> void writeJsonToFile(T t, File file) throws IOException {
		String jsonStr = JSONObject.toJSONString(t, SerializerFeature.PrettyFormat);
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file)));
		bw.write(jsonStr);
		bw.close();
	}

	/**
	 * @param t
	 * @param filename
	 * @throws IOException
	 *             Return:void Description:将对象的Json数据写入文件。
	 */
	public static <T> void writeJsonToFile(T t, String filename) throws IOException {
		writeJsonToFile(t, new File(filename));
	}

	/**
	 * @param cls
	 * @param file
	 * @return
	 * @throws IOException
	 *             Return:T Description:将文件中的Json数据转换成Object对象
	 */
	public static <T> T readJsonFromFile(Class<T> cls, File file) throws IOException {
		StringBuilder strBuilder = new StringBuilder();
		BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
		String line = null;
		while ((line = br.readLine()) != null) {
			strBuilder.append(line);
		}
		br.close();
		return JSONObject.parseObject(strBuilder.toString(), cls);
	}

	/**
	 * Author:Jack Time:2017年9月2日下午4:22:30
	 * 
	 * @param cls
	 * @param filename
	 * @return
	 * @throws IOException
	 *             Return:T Description:将文件中的Json数据转换成Object对象
	 */
	public static <T> T readJsonFromFile(Class<T> cls, String filename) throws IOException {
		return readJsonFromFile(cls, new File(filename));
	}

	/**
	 * Author:Jack Time:2017年9月2日下午4:23:06
	 * 
	 * @param typeReference
	 * @param file
	 * @return
	 * @throws IOException
	 *             Return:T Description:从文件中读取出Json对象
	 */
	public static <T> T readJsonFromFile(TypeReference<T> typeReference, File file) throws IOException {
		StringBuilder strBuilder = new StringBuilder();
		BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
		String line = null;
		while ((line = br.readLine()) != null) {
			strBuilder.append(line);
		}
		br.close();
		return JSONObject.parseObject(strBuilder.toString(), typeReference);
	}

	/**
	 * Author:Jack Time:2017年9月2日下午4:23:11
	 * 
	 * @param typeReference
	 * @param filename
	 * @return
	 * @throws IOException
	 *             Return:T Description:从文件中读取出Json对象
	 */
	public static <T> T readJsonFromFile(TypeReference<T> typeReference, String filename) throws IOException {
		return readJsonFromFile(typeReference, new File(filename));
	}

}

　　

原文：https://blog.csdn.net/zhang150114/article/details/90411800