参考:http://www.cnblogs.com/hoojo/archive/2011/04/22/2024628.html
在其基础上做了稍微调整
详情见附件
jackson API文档:http://tool.oschina.net/apidocs/apidoc?api=jackson-1.9.9
Jackson可以轻松的将Java对象转换成json对象和xml文档,同样也可以将json、xml转换成Java对象。相比json-lib框架,Jackson所依赖的jar包较少,简单易用并且性能也要相对高些。而且Jackson社区相对比较活跃,更新速度也比较快。
一、准备工作
pom.xml 里关联jar包如下:
- <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
- xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
- <modelVersion>4.0.0</modelVersion>
- <groupId>com.waegg</groupId>
- <artifactId>jacksonTest</artifactId>
- <version>0.0.1-SNAPSHOT</version>
- <dependencies>
- <dependency>
- <groupId>junit</groupId>
- <artifactId>junit</artifactId>
- <version>4.12</version>
- </dependency>
- <dependency>
- <groupId>org.codehaus.jackson</groupId>
- <artifactId>jackson-mapper-asl</artifactId>
- <version>1.9.13</version>
- </dependency>
- <dependency>
- <groupId>com.fasterxml.jackson.dataformat</groupId>
- <artifactId>jackson-dataformat-xml</artifactId>
- <version>2.7.1</version>
- </dependency>
- </dependencies>
- <packaging>war</packaging>
- </project>
二、Bean代码
AccountBean :
- package com.bugyun.pojo;
- public class AccountBean {
- private int id;
- private String name;
- private String email;
- private String address;
- private Birthday birthday;
- // getter、setter
- @Override
- public String toString() {
- return this.name + "#" + this.id + "#" + this.address + "#" + this.birthday + "#" + this.email;
- }
- 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 String getEmail() {
- return email;
- }
- public void setEmail(String email) {
- this.email = email;
- }
- public String getAddress() {
- return address;
- }
- public void setAddress(String address) {
- this.address = address;
- }
- public Birthday getBirthday() {
- return birthday;
- }
- public void setBirthday(Birthday birthday) {
- this.birthday = birthday;
- }
- }
Birthday:
- package com.bugyun.pojo;
- public class Birthday {
- private String birthday;
- public Birthday(String birthday) {
- super();
- this.birthday = birthday;
- }
- // getter、setter
- public Birthday() {
- }
- public String getBirthday() {
- return birthday;
- }
- public void setBirthday(String birthday) {
- this.birthday = birthday;
- }
- @Override
- public String toString() {
- return this.birthday;
- }
- }
三、测试代码
- package com.bugyun.test;
- import java.io.IOException;
- import java.io.StringWriter;
- import java.util.ArrayList;
- import java.util.HashMap;
- import java.util.Iterator;
- import java.util.List;
- import java.util.Map;
- import java.util.Set;
- import org.codehaus.jackson.JsonEncoding;
- import org.codehaus.jackson.JsonGenerationException;
- import org.codehaus.jackson.JsonGenerator;
- import org.codehaus.jackson.JsonParseException;
- import org.codehaus.jackson.map.JsonMappingException;
- import org.codehaus.jackson.map.ObjectMapper;
- import org.junit.After;
- import org.junit.Before;
- import org.junit.Test;
- import com.bugyun.pojo.AccountBean;
- import com.fasterxml.jackson.dataformat.xml.XmlMapper;
- /**
- * 项目名称:jacksonTest
- * 类名称:JacksonTest.java
- * 类描述:
- * 创建人:beyond
- * 创建时间:2016年2月24日 上午11:24:33
- * 修改人:
- * 修改时间:
- * 修改备注:
- * @version
- */
- public class JacksonTest {
- private JsonGenerator jsonGenerator = null;
- private ObjectMapper objectMapper = null;
- private AccountBean bean = null;
- @Before
- public void init() {
- bean = new AccountBean();
- bean.setAddress("js_wuxi");
- bean.setEmail("bugyun@hotmail.com");
- bean.setId(1);
- bean.setName("bugyun");
- objectMapper = new ObjectMapper();
- try {
- jsonGenerator = objectMapper.getJsonFactory().createJsonGenerator(System.out, JsonEncoding.UTF8);
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- @After
- public void destory() {
- try {
- if (jsonGenerator != null) {
- jsonGenerator.flush();
- }
- if (!jsonGenerator.isClosed()) {
- jsonGenerator.close();
- }
- jsonGenerator = null;
- objectMapper = null;
- bean = null;
- System.gc();
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- /**
- *
- * @description: JavaBean(Entity/Model)转换成JSON
- * 上面分别利用JsonGenerator的writeObject方法和ObjectMapper的writeValue方法完成对Java对象的转换,二者传递的参数及构造的方式不同;
- * JsonGenerator的创建依赖于ObjectMapper对象。
- * 也就是说如果你要使用JsonGenerator来转换JSON,那么你必须创建一个ObjectMapper。
- * 但是你用ObjectMapper来转换JSON,则不需要JSONGenerator。objectMapper的writeValue方法可以将一个Java对象转换成JSON。
- * 这个方法的参数一,需要提供一个输出流,转换后可以通过这个流来输出转换后的内容。
- * 或是提供一个File,将转换后的内容写入到File中。当然,这个参数也可以接收一个JSONGenerator,然后通过JSONGenerator来输出转换后的信息。
- * 第二个参数是将要被转换的Java对象。如果用三个参数的方法,那么是一个Config。
- * 这个config可以提供一些转换时的规则,过指定的Java对象的某些属性进行过滤或转换等。
- *
- * 输出:
- * jsonGenerator {"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}
- * ObjectMapper {"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}
- * @return void
- * @throws
- * @author beyond
- * @data:2016年2月24日上午11:34:53
- */
- @Test
- public void writeEntityJSON() {
- try {
- System.out.println("jsonGenerator");
- jsonGenerator.writeObject(bean);
- System.out.println("\nObjectMapper");
- objectMapper.writeValue(System.out, bean);
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- /**
- * @description: 将Map集合转换成Json字符串
- * 输出:
- * jsonGenerator {"name":"bugyun","account":{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}}
- * ObjectMapper {"name":"bugyun","account":{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}}
- * @return void
- * @throws
- * @author beyond
- * @data:2016年2月24日上午11:41:48
- */
- @Test
- public void writeMapJSON() {
- try {
- Map<String, Object> map = new HashMap<String, Object>();
- map.put("name", bean.getName());
- map.put("account", bean);
- System.out.println("jsonGenerator");
- jsonGenerator.writeObject(map);
- System.out.println("\n ObjectMapper");
- objectMapper.writeValue(System.out, map);
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- /**
- *
- * @description: 将List集合转换成json
- * 外面就是多了个[]中括号;同样Array也可以转换,转换的JSON和上面的结果是一样的
- * 输出:
- * jsonGenerator [{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}]
- * ObjectMapper 1###[{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}]
- * 2###[{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}]
- * @return void
- * @throws
- * @author beyond
- * @data:2016年2月24日上午11:46:41
- */
- @Test
- public void writeListJSON() {
- try {
- List<AccountBean> list = new ArrayList<AccountBean>();
- list.add(bean);
- System.out.println("jsonGenerator");
- jsonGenerator.writeObject(list);
- System.out.println("\nObjectMapper");
- System.out.println("1###" + objectMapper.writeValueAsString(list));
- System.out.print("2###");
- objectMapper.writeValue(System.out, list);
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- /**
- * @description: 复杂的Java类型的JSON转换
- * 输出:
- * {"user":{"name":"jackson","sex":true,"age":22},"infos":[22,"this is array"]}
- * {"user":{"id":1,"name":"haha","email":"email","address":"address","birthday":null},"infos":["a","b","c"]}
- * @return void
- * @throws
- * @author beyond
- * @data:2016年2月24日下午1:08:06
- */
- @Test
- public void writeOthersJSON() {
- try {
- String[] arr = { "a", "b", "c" };
- //Object
- jsonGenerator.writeStartObject();//{
- jsonGenerator.writeObjectFieldStart("user");//user:{
- jsonGenerator.writeStringField("name", "jackson");//name:jackson
- jsonGenerator.writeBooleanField("sex", true);//sex:true
- jsonGenerator.writeNumberField("age", 22);//age:22
- jsonGenerator.writeEndObject();//}
- jsonGenerator.writeArrayFieldStart("infos");//infos:[
- jsonGenerator.writeNumber(22);//22
- jsonGenerator.writeString("this is array");//this is array
- jsonGenerator.writeEndArray();//]
- jsonGenerator.writeEndObject();//}
- // ********************************************
- AccountBean bean = new AccountBean();
- bean.setAddress("address");
- bean.setEmail("email");
- bean.setId(1);
- bean.setName("haha");
- jsonGenerator.writeStartObject();//{
- jsonGenerator.writeObjectField("user", bean);//user:{bean}
- jsonGenerator.writeObjectField("infos", arr);//infos:[array]
- jsonGenerator.writeEndObject();//}
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
- /**
- * @description: 将json字符串转换成JavaBean对象
- * 用到了ObjectMapper这个对象的readValue这个方法,这个方法需要提供2个参数。
- * 第一个参数就是解析的JSON字符串,
- * 第二个参数是将这个JSON解析持什么Java对象,Java对象的类型。当然,还有其他相同签名方法。
- *
- * 输出:
- * haha
- * haha#1#address#null#email
- * @return void
- * @throws
- * @author beyond
- * @data:2016年2月24日下午3:37:50
- */
- @Test
- public void readJson2Entity() {
- String json = "{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}";
- try {
- AccountBean acc = objectMapper.readValue(json, AccountBean.class);
- System.out.println(acc.getName());
- System.out.println(acc);
- } catch (JsonParseException e) {
- e.printStackTrace();
- } catch (JsonMappingException e) {
- e.printStackTrace();
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- /**
- * @description: json字符串转换成list<map>
- * 输出:
- * address:address2
- * name:haha2
- * id:2
- * email:email2
- * address:address
- * name:haha
- * id:1
- * email:email
- * @return void
- * @throws
- * @author beyond
- * @data:2016年2月25日下午4:39:39
- */
- @Test
- public void readJson2List() {
- String json = "[{\"address\": \"address2\",\"name\":\"haha2\",\"id\":2,\"email\":\"email2\"},"
- + "{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}]";
- try {
- List<Map<String, Object>> list = objectMapper.readValue(json, List.class);
- // System.out.println(list.size());
- for (int i = 0; i < list.size(); i++) {
- Map<String, Object> map = list.get(i);
- Set<String> set = map.keySet();
- for (Iterator it = set.iterator(); it.hasNext();) {
- String key = (String) it.next();
- System.out.println(key + ":" + map.get(key));
- }
- }
- } catch (JsonParseException e) {
- e.printStackTrace();
- } catch (JsonMappingException e) {
- e.printStackTrace();
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- /**
- *
- * @description: json字符串转换成Array
- * 输出:
- * haha2#2#address2#null#email2
- * haha#1#address#null#email
- * @return void
- * @throws
- * @author beyond
- * @data:2016年2月25日下午4:44:09
- */
- @Test
- public void readJson2Array() {
- String json = "[{\"address\": \"address2\",\"name\":\"haha2\",\"id\":2,\"email\":\"email2\"},"
- + "{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}]";
- try {
- AccountBean[] arr = objectMapper.readValue(json, AccountBean[].class);
- // System.out.println(arr.length);
- for (int i = 0; i < arr.length; i++) {
- System.out.println(arr[i]);
- }
- } catch (JsonParseException e) {
- e.printStackTrace();
- } catch (JsonMappingException e) {
- e.printStackTrace();
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- /**
- *
- * @description: json字符串转换Map集合
- * 输出:
- * success:true
- * A:{address=address2, name=haha2, id=2, email=email2}
- * B:{address=address, name=haha, id=1, email=email}
- * @return void
- * @throws
- * @author beyond
- * @data:2016年2月25日下午4:48:40
- */
- @Test
- public void readJson2Map() {
- String json = "{\"success\":true,\"A\":{\"address\": \"address2\",\"name\":\"haha2\",\"id\":2,\"email\":\"email2\"},"
- + "\"B\":{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}}";
- try {
- Map<String, Map<String, Object>> maps = objectMapper.readValue(json, Map.class);
- // System.out.println(maps.size());
- Set<String> key = maps.keySet();
- Iterator<String> iter = key.iterator();
- while (iter.hasNext()) {
- String field = iter.next();
- System.out.println(field + ":" + maps.get(field));
- }
- } catch (JsonParseException e) {
- e.printStackTrace();
- } catch (JsonMappingException e) {
- e.printStackTrace();
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- /**
- * @description: java Object 转换为 xml
- * 输出:
- * <ArrayList xmlns=""><item><id>1</id><name>bugyun</name><email>bugyun@hotmail.com</email><address>js_wuxi</address><birthday/></item></ArrayList>
- * <HashMap xmlns=""><A><id>1</id><name>bugyun</name><email>bugyun@hotmail.com</email><address>js_wuxi</address><birthday/></A></HashMap>
- * @return void
- * @throws
- * @author beyond
- * @data:2016年2月26日上午9:20:49
- */
- @Test
- public void writeObject2Xml() {
- XmlMapper xml = new XmlMapper();
- try {
- //javaBean转换成xml
- //xml.writeValue(System.out, bean);
- StringWriter sw = new StringWriter();
- xml.writeValue(sw, bean);
- // System.out.println(sw.toString());
- // List转换成xml
- List<AccountBean> list = new ArrayList<AccountBean>();
- list.add(bean);
- System.out.println(xml.writeValueAsString(list));
- // Map转换xml文档
- Map<String, AccountBean> map = new HashMap<String, AccountBean>();
- map.put("A", bean);
- System.out.println(xml.writeValueAsString(map));
- } catch (JsonGenerationException e) {
- e.printStackTrace();
- } catch (JsonMappingException e) {
- e.printStackTrace();
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- }
引用原文:http://bugyun.iteye.com/blog/2278997
写博客是为了记住自己容易忘记的东西,另外也是对自己工作的总结,文章可以转载,无需版权。希望尽自己的努力,做到更好,大家一起努力进步!
如果有什么问题,欢迎大家一起探讨,代码如有问题,欢迎各位大神指正!