Jackson. Jar usage record

Jackson. Jar usage record

I 've been using json-lib.jar before, and recently found online that this Jackson. jar is better

package com.spring.controller;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.OutputStream;import java.util.ArrayList;import java.util.Date;import java.util.List;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.codehaus.jackson.JsonEncoding;import org.codehaus.jackson.JsonGenerator;import org.codehaus.jackson.map.ObjectMapper;import org.codehaus.jackson.map.ObjectWriter;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.servlet.ModelAndView;@Controllerpublic class JacksonController {@RequestMapping(value="user/jackson", method = {RequestMethod.POST,RequestMethod.GET})public ModelAndView PostJsonTest(HttpServletRequest request,HttpServletResponse response) throws IOException{ModelAndView mav=new ModelAndView();mav.addObject("time", new Date());JsonGenerator jsonGenerator = null;ObjectMapper objectMapper = new ObjectMapper();jsonGenerator = objectMapper.getJsonFactory().createJsonGenerator(System.out, JsonEncoding.UTF8);//将java对象转为jsonUserJson userJson=new UserJson();userJson.setUsername("小米");userJson.setId("31231");userJson.setPwd("123456");userJson.setAge(24);userJson.setAddress("广州");userJson.setTel(13676586);//objectMapper.writeValue(jsonGenerator, userJson);String jsonStr = objectMapper.writeValueAsString(userJson);//writeObject可以转换java对象，eg:JavaBean/Map/List/Array等//jsonGenerator.writeObject(userJson);System.out.println("-----json-------");String jsonSS="{\"address\":\"广州\",\"id\":\"31231\",\"username\":\"小米\",\"tel\":13676586,\"age\":24,\"pwd\":\"123456\"}";System.out.println("--------字符串json-------"+jsonSS);System.out.println("------标准jsonStr--------"+jsonStr);mav.addObject("jsonStr", jsonStr);mav.addObject("jsonss", jsonSS.toString());mav.setViewName("json/jackson");//将list集合转为jsonList<UserJson> list=new ArrayList<UserJson>();for(int i=0;i<5;i++){UserJson u3=new UserJson();u3.setId("ooo"+i);u3.setUsername("小小明"+i);u3.setPwd("123456"+i);u3.setAge(20+i);u3.setAddress("广州"+i);u3.setTel(13664+i*i*i);list.add(u3);}String jsonlist = objectMapper.writeValueAsString(list);mav.addObject("jsonlist", jsonlist.toString());mav.setViewName("json/jackson");return mav;}/** * list转为json数组 */public String writeListToJsonArray() throws IOException {      /*List<Event> list = new ArrayList<Event>(2);    list.add(new Event("a1","a2"));    list.add(new Event("b1","b2"));*/List<String> list = new ArrayList<String>();    list.add("A2");    list.add("B2");    OutputStream out = new ByteArrayOutputStream();    ObjectMapper mapper = new ObjectMapper();    mapper.writeValue(out, list);    byte[] data = ((ByteArrayOutputStream) out).toByteArray();    System.out.println(new String(data));    String result=new String(data);    return result;}/** * list转为json数组 */public String writeListToJsonArray2() throws IOException { ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();final ObjectMapper mapper = new ObjectMapper();List<String> list = new ArrayList<String>();    list.add("A2");    list.add("B2");String jsonArray = ow.writeValueAsString(list);System.out.println(jsonArray);return jsonArray;}}///java对象class UserJson{private String id;private String username;private String pwd;private Integer age;private int tel;private String address;public String getId() {return id;}public void setId(String id) {this.id = id;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPwd() {return pwd;}public void setPwd(String pwd) {this.pwd = pwd;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public int getTel() {return tel;}public void setTel(int tel) {this.tel = tel;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}}

Convert list to JSON array (Java Main Program)

package com.main.java.demo;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.OutputStream;import java.util.ArrayList;import java.util.List;import org.codehaus.jackson.map.ObjectMapper;import org.codehaus.jackson.map.ObjectWriter;public class JacksonDemo {public static void main(String args[]) throws IOException{//writeListToJsonArray();//writeListToJsonArray2();//writeListToJsonArray3();//writeListToJsonArray4();//writeListToJsonArray5();writeListToJsonArray6();}/** * list转为json数组 */public static String writeListToJsonArray() throws IOException {      /*List<Event> list = new ArrayList<Event>(2);    list.add(new Event("a1","a2"));    list.add(new Event("b1","b2"));*//*List<String> list = new ArrayList<String>();    list.add("A2");    list.add("B2");*//*List<Integer> list = new ArrayList<Integer>();    list.add(12);    list.add(45);    list.add(5);*/List<Float> list = new ArrayList<Float>();    list.add((float) 12.32);    list.add((float) 45.12);    list.add((float) 5.09);    OutputStream out = new ByteArrayOutputStream();    ObjectMapper mapper = new ObjectMapper();    mapper.writeValue(out, list);    byte[] data = ((ByteArrayOutputStream) out).toByteArray();    System.out.println(new String(data));    String result=new String(data);    return result;}/** * list转为json数组 */public static String writeListToJsonArray2() throws IOException { ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();final ObjectMapper mapper = new ObjectMapper();List<String> list = new ArrayList<String>();    list.add("A2");    list.add("B2");        //// Using writeValueAsStringString jsonArray = ow.writeValueAsString(list);System.out.println(jsonArray);return jsonArray;}/** * list转为json数组 */public static String writeListToJsonArray3() throws IOException { ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();ObjectMapper mapper = new ObjectMapper();List<String> list = new ArrayList<String>();list.add("A23");list.add("B23");//// Using Bytesbyte[] data = mapper.writeValueAsBytes(list);String jsonArray = new String(data, "UTF-8");System.out.println(jsonArray);return jsonArray;}/** * list转为json数组 */public static String writeListToJsonArray4() throws IOException { ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();ObjectMapper mapper = new ObjectMapper();List<String> list = new ArrayList<String>();list.add("A234");list.add("B234");// Using ByteArrayOutputStream with new String()OutputStream os = new ByteArrayOutputStream();mapper.writeValue(os, list);byte[] data = ((ByteArrayOutputStream) os).toByteArray();String jsonArray = new String(data, "UTF-8");System.out.println(jsonArray);return jsonArray;}/** * list转为json数组 */public static String writeListToJsonArray5() throws IOException { ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();ObjectMapper mapper = new ObjectMapper();List<String> list = new ArrayList<String>();list.add("A2345");list.add("B2345");// Using ByteArrayOutputStreamfinal OutputStream os = new ByteArrayOutputStream();mapper.writeValue(os, list);String jsonArray = ((ByteArrayOutputStream) os).toString("UTF-8");System.out.println(jsonArray);return jsonArray;}/** * list转为json数组 */public static String writeListToJsonArray6() throws IOException { ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();ObjectMapper mapper = new ObjectMapper();List<String> list = new ArrayList<String>();list.add("A23456");list.add("B23456");// Using writeValueAsStringString jsonArray = mapper.writeValueAsString(list);System.out.println(jsonArray);return jsonArray;}}

JSP page:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">




 
 





 
Jackson. Jar usage record