前一段工作中总会遇到使用Java处理JSON的情况，大部分都使用的是开源工具Jackson实现的。
因此总结一下发上来，希望对看到的人有所帮助。
------------------------------------------------------------
Jackson中有个ObjectMapper类很是实用，用于Java对象与JSON的互换。
1、Java对象转换为JSON：
User user=new User(); //Java Object
ObjectMapper mapper = new ObjectMapper();
mapper.writeValueAsString(user); //返回字符串
//输出格式化后的字符串(有性能损耗)
mapper.defaultPrettyPrintingWriter().writeValueAsString(user);
mapper.writeValue(new File(&c:\\user.json&), user); //指定文件写入
//设置序列化配置(全局),设置序列化时不输出空值.
sharedMapper.getSerializationConfig().setSerializationInclusion(Inclusion.NON_NULL);
2、JSON反序列化为Java对象：
ObjectMapper mapper = new ObjectMapper();
//解析器支持解析单引号
mapper.configure(Feature.ALLOW_SINGLE_QUOTES,true);
//解析器支持解析结束符
mapper.configure(Feature.ALLOW_UNQUOTED_CONTROL_CHARS,true);
HashMap jsonMap = mapper.readValue(json,HashMap.class); //转换为HashMap对象
二、Jackson支持3种使用方式:
1、Data Binding：最方便使用.
(1)Full Data Binding：
Java代码 &
private&static&final&String&MODEL_BINDING&=&&{\&name\&:\&name1\&,\&type\&:1}&;&&&&&&public&void&fullDataBinding()&throws&Exception{&&&&&&&&&&ObjectMapper&mapper&=&new&ObjectMapper();&&&&&&&&&&Model&user&=&mapper.readValue(MODEL_BINDING,&Model.class);&&&&&&&&&&System.out.println(user.getName());&&&&&&&&&&System.out.println(user.getType());&&&&&&}&&
private static final String MODEL_BINDING = &{\&name\&:\&name1\&,\&type\&:1}&;
public void fullDataBinding() throws Exception{
ObjectMapper mapper = new ObjectMapper();
Model user = mapper.readValue(MODEL_BINDING, Model.class);//readValue到一个实体类中.
System.out.println(user.getName());
System.out.println(user.getType());
Java代码 &
private&static&class&Model{&&&&&&&&&&private&String&&&&&&&&&&&private&int&&&&&&&&&&&&&&&&&&&&&public&String&getName()&{&&&&&&&&&&&&&&return&&&&&&&&&&&}&&&&&&&&&&public&void&setName(String&name)&{&&&&&&&&&&&&&&this.name&=&&&&&&&&&&&}&&&&&&&&&&public&int&getType()&{&&&&&&&&&&&&&&return&&&&&&&&&&&}&&&&&&&&&&public&void&setType(int&type)&{&&&&&&&&&&&&&&this.type&=&&&&&&&&&&&}&&&&&&}&&
private static class Model{
public String getName() {
public void setName(String name) {
this.name =
public int getType() {
public void setType(int type) {
this.type =
(2)Raw Data Binding：
Java代码 &
&&&&&&&&&&&&&&&&public&void&rawDataBinding()&throws&Exception{&&&&&&&&&&ObjectMapper&mapper&=&new&ObjectMapper();&&&&&&&&&&HashMap&map&=&mapper.readValue(MODEL_BINDING,HashMap.class);&&&&&&&&&&System.out.println(map.get(&name&));&&&&&&&&&&System.out.println(map.get(&type&));&&&&&&}&&
Concrete Java types that Jackson will use for simple data binding are:
LinkedHashMap&String,Object&
ArrayList&Object&
number(no fraction) Integer, Long or BigInteger (smallest applicable)
number(fraction) Double(configurable to use BigDecimal)
true|false
public void rawDataBinding() throws Exception{
ObjectMapper mapper = new ObjectMapper();
HashMap map = mapper.readValue(MODEL_BINDING,HashMap.class);//readValue到一个原始数据类型.
System.out.println(map.get(&name&));
System.out.println(map.get(&type&));
&(3)generic Data Binding：
Java代码 &
private&static&final&String&GENERIC_BINDING&=&&{\&key1\&:{\&name\&:\&name2\&,\&type\&:2},\&key2\&:{\&name\&:\&name3\&,\&type\&:3}}&;&&&&&&public&void&genericDataBinding()&throws&Exception{&&&&&&&&&&ObjectMapper&mapper&=&new&ObjectMapper();&&&&&&&&&&HashMap&String,Model&&modelMap&=&mapper.readValue(GENERIC_BINDING,new&TypeReference&HashMap&String,Model&&(){});&&&&&&&&&&Model&model&=&modelMap.get(&key2&);&&&&&&&&&&System.out.println(model.getName());&&&&&&&&&&System.out.println(model.getType());&&&&&&}&&
private static final String GENERIC_BINDING = &{\&key1\&:{\&name\&:\&name2\&,\&type\&:2},\&key2\&:{\&name\&:\&name3\&,\&type\&:3}}&;
public void genericDataBinding() throws Exception{
ObjectMapper mapper = new ObjectMapper();
HashMap&String,Model& modelMap = mapper.readValue(GENERIC_BINDING,new TypeReference&HashMap&String,Model&&(){});//readValue到一个范型数据中.
Model model = modelMap.get(&key2&);
System.out.println(model.getName());
System.out.println(model.getType());
2、Tree Model：最灵活。
Java代码 &
private&static&final&String&TREE_MODEL_BINDING&=&&{\&treekey1\&:\&treevalue1\&,\&treekey2\&:\&treevalue2\&,\&children\&:[{\&childkey1\&:\&childkey1\&}]}&;&&&&&&public&void&treeModelBinding()&throws&Exception{&&&&&&&&&&ObjectMapper&mapper&=&new&ObjectMapper();&&&&&&&&&&JsonNode&rootNode&=&mapper.readTree(TREE_MODEL_BINDING);&&&&&&&&&&&&&&&&&&&&String&treekey2value&=&rootNode.path(&treekey2&).getTextValue();&&&&&&&&&&System.out.println(&treekey2value:&&+&treekey2value);&&&&&&&&&&JsonNode&childrenNode&=&rootNode.path(&children&);&&&&&&&&&&String&childkey1Value&=&childrenNode.get(0).path(&childkey1&).getTextValue();&&&&&&&&&&System.out.println(&childkey1Value:&+childkey1Value);&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&ObjectNode&root&=&mapper.createObjectNode();&&&&&&&&&&&&&&&&&&&&ObjectNode&node1&=&mapper.createObjectNode();&&&&&&&&&&node1.put(&nodekey1&,1);&&&&&&&&&&node1.put(&nodekey2&,2);&&&&&&&&&&&&&&&&&&&&root.put(&child&,node1);&&&&&&&&&&&&&&&&&&&&ArrayNode&arrayNode&=&mapper.createArrayNode();&&&&&&&&&&arrayNode.add(node1);&&&&&&&&&&arrayNode.add(1);&&&&&&&&&&&&&&&&&&&&root.put(&arraynode&,&arrayNode);&&&&&&&&&&&&&&&&&&&&JsonNode&valueToTreeNode&=&mapper.valueToTree(TREE_MODEL_BINDING);&&&&&&&&&&&&&&&&&&&&root.put(&valuetotreenode&,valueToTreeNode);&&&&&&&&&&&&&&&&&&&&JsonNode&bindJsonNode&=&mapper.readValue(GENERIC_BINDING,&JsonNode.class);&&&&&&&&&&&&&&&&&&&&root.put(&bindJsonNode&,bindJsonNode);&&&&&&&&&&System.out.println(mapper.writeValueAsString(root));&&&&&&}&&
private static final String TREE_MODEL_BINDING = &{\&treekey1\&:\&treevalue1\&,\&treekey2\&:\&treevalue2\&,\&children\&:[{\&childkey1\&:\&childkey1\&}]}&;
public void treeModelBinding() throws Exception{
ObjectMapper mapper = new ObjectMapper();
JsonNode rootNode = mapper.readTree(TREE_MODEL_BINDING);
//path与get作用相同,但是当找不到该节点的时候,返回missing node而不是Null.
String treekey2value = rootNode.path(&treekey2&).getTextValue();//
System.out.println(&treekey2value:& + treekey2value);
JsonNode childrenNode = rootNode.path(&children&);
String childkey1Value = childrenNode.get(0).path(&childkey1&).getTextValue();
System.out.println(&childkey1Value:&+childkey1Value);
//创建根节点
ObjectNode root = mapper.createObjectNode();
//创建子节点1
ObjectNode node1 = mapper.createObjectNode();
node1.put(&nodekey1&,1);
node1.put(&nodekey2&,2);
//绑定子节点1
root.put(&child&,node1);
//数组节点
ArrayNode arrayNode = mapper.createArrayNode();
arrayNode.add(node1);
arrayNode.add(1);
//绑定数组节点
root.put(&arraynode&, arrayNode);
//JSON读到树节点
JsonNode valueToTreeNode = mapper.valueToTree(TREE_MODEL_BINDING);
//绑定JSON节点
root.put(&valuetotreenode&,valueToTreeNode);
//JSON绑定到JSON节点对象
JsonNode bindJsonNode = mapper.readValue(GENERIC_BINDING, JsonNode.class);//绑定JSON到JSON节点对象.
//绑定JSON节点
root.put(&bindJsonNode&,bindJsonNode);
System.out.println(mapper.writeValueAsString(root));
3、Streaming API：最佳性能。
见官方文档例子。
1、&Jackson官方教程示例
2、&Jackson在线API文档
3、&JSON工具性能比较:json-lib和jackson进行Java对象到json字符串序列化。
参考知识库
* 以上用户言论只代表其个人观点，不代表CSDN网站的观点或立场
访问：24449次
排名：千里之外
原创：65篇
转载：27篇
(1)(1)(3)(2)(8)(6)(9)(4)(16)(27)(16)trackbacks-0
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。前面有介绍过json-lib这个框架，在线博文：http://www./lib/view/open3.html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1、 下载依赖库jar包Jackson的jar all下载地址：然后在工程中导入这个jar包即可开始工作官方示例：因为下面的程序是用junit测试用例运行的，所以还得添加junit的jar包。版本是junit-4.2.8如果你需要转换xml，那么还需要stax2-api.jar2、 测试类基本代码如下package com.hoo.&import java.io.IOEimport java.io.StringWimport java.util.ArrayLimport java.util.HashMimport java.util.Iimport java.util.LinkedHashMimport java.util.Limport java.util.Mimport java.util.Simport org.codehaus.jackson.JsonEimport org.codehaus.jackson.JsonGenerationEimport org.codehaus.jackson.JsonGimport org.codehaus.jackson.JsonParseEimport org.codehaus.jackson.map.JsonMappingEimport org.codehaus.jackson.map.ObjectMimport org.codehaus.jackson.node.JsonNodeFimport org.codehaus.jackson.xml.XmlMimport org.junit.Aimport org.junit.Bimport org.junit.Timport com.hoo.entity.AccountB&/** * &b&function:&/b&Jackson 将java对象转换成JSON字符串，也可以将JSON字符串转换成java对象 * jar-lib-version: jackson-all-1.6.2 * jettison-1.0.1 * @author hoojo * @createDate
下午04:54:53 * @file JacksonTest.java * @package com.hoo.test * @project Spring3 * @blog http://blog.csdn.net/IBM_hoojo * @email hoojo_@ * @version 1.0 */@SuppressWarnings("unchecked")public class JacksonTest {
private JsonGenerator jsonGenerator =
private ObjectMapper objectMapper =
private AccountBean bean =
public void init() {
bean = new AccountBean();
bean.setAddress("china-Guangzhou");
bean.setEmail("hoojo_@");
bean.setId(1);
bean.setName("hoojo");
objectMapper = new ObjectMapper();
jsonGenerator = objectMapper.getJsonFactory().createJsonGenerator(System.out, JsonEncoding.UTF8);
} catch (IOException e) {
e.printStackTrace();
public void destory() {
if (jsonGenerator != null) {
jsonGenerator.flush();
if (!jsonGenerator.isClosed()) {
jsonGenerator.close();
jsonGenerator =
objectMapper =
System.gc();
} catch (IOException e) {
e.printStackTrace();
}}3、 所需要的JavaEntitypackage com.hoo.&public class AccountBean {
private int
//getter、setter
public String toString() {
return this.name + "#" + this.id + "#" + this.address + "#" + this.birthday + "#" + this.
}}Birthdaypackage com.hoo.&public class Birthday {
public Birthday(String birthday) {
this.birthday =
//getter、setter&
public Birthday() {}
public String toString() {
return this.
}}二、Java对象转换成JSON1、 JavaBean(Entity/Model)转换成JSON/** * &b&function:&/b&将java对象转换成json字符串 * @author hoojo * @createDate
下午06:01:10 */@Testpublic void writeEntityJSON() {
System.out.println("jsonGenerator");
//writeObject可以转换java对象，eg:JavaBean/Map/List/Array等
jsonGenerator.writeObject(bean);
System.out.println();
System.out.println("ObjectMapper");
//writeValue具有和writeObject相同的功能
objectMapper.writeValue(System.out, bean);
} catch (IOException e) {
e.printStackTrace();
}}运行后结果如下：jsonGenerator{"address":"china-Guangzhou","name":"hoojo","id":1,"birthday":null,"email":"hoojo_@"}ObjectMapper{"address":"china-Guangzhou","name":"hoojo","id":1,"birthday":null,"email":"hoojo_@"}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。2、 将Map集合转换成Json字符串/** * &b&function:&/b&将map转换成json字符串 * @author hoojo * @createDate
下午06:05:26 */@Testpublic void writeMapJSON() {
Map&String, Object& map = new HashMap&String, Object&();
map.put("name", bean.getName());
map.put("account", bean);
bean = new AccountBean();
bean.setAddress("china-Beijin");
bean.setEmail("");
map.put("account2", bean);
System.out.println("jsonGenerator");
jsonGenerator.writeObject(map);
System.out.println("");
System.out.println("objectMapper");
objectMapper.writeValue(System.out, map);
} catch (IOException e) {
e.printStackTrace();
}}转换后结果如下：jsonGenerator{"account2":{"address":"china-Beijin","name":null,"id":0,"birthday":null,"email":""},"name":"hoojo","account":{"address":"china-Guangzhou","name":"hoojo","id":1,"birthday":null,"email":"hoojo_@"}}objectMapper{"account2":{"address":"china-Beijin","name":null,"id":0,"birthday":null,"email":""},"name":"hoojo","account":{"address":"china-Guangzhou","name":"hoojo","id":1,"birthday":null,"email":"hoojo_@"}}3、 将List集合转换成json/** * &b&function:&/b&将list集合转换成json字符串 * @author hoojo * @createDate
下午06:05:59 */@Testpublic void writeListJSON() {
List&AccountBean& list = new ArrayList&AccountBean&();
list.add(bean);
bean = new AccountBean();
bean.setId(2);
bean.setAddress("address2");
bean.setEmail("email2");
bean.setName("haha2");
list.add(bean);
System.out.println("jsonGenerator");
//list转换成JSON字符串
jsonGenerator.writeObject(list);
System.out.println();
System.out.println("ObjectMapper");
//用objectMapper直接返回list转换成的JSON字符串
System.out.println("1###" + objectMapper.writeValueAsString(list));
System.out.print("2###");
//objectMapper list转换成JSON字符串
objectMapper.writeValue(System.out, list);
} catch (IOException e) {
e.printStackTrace();
}}结果如下：jsonGenerator[{"address":"china-Guangzhou","name":"hoojo","id":1,"birthday":null,"email":"hoojo_@"},{"address":"address2","name":"haha2","id":2,"birthday":null,"email":"email2"}]ObjectMapper1###[{"address":"china-Guangzhou","name":"hoojo","id":1,"birthday":null,"email":"hoojo_@"},{"address":"address2","name":"haha2","id":2,"birthday":null,"email":"email2"}]2###[{"address":"china-Guangzhou","name":"hoojo","id":1,"birthday":null,"email":"hoojo_@"},{"address":"address2","name":"haha2","id":2,"birthday":null,"email":"email2"}]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，这里就不再转换了。~.~4、下面来看看jackson提供的一些类型，用这些类型完成json转换；如果你使用这些类型转换JSON的话，那么你即使没有 JavaBean(Entity)也可以完成复杂的Java类型的JSON转换。下面用到这些类型构建一个复杂的Java对象，并完成JSON转换。@Testpublic void writeOthersJSON() {
String[] arr = { "a", "b", "c" };
System.out.println("jsonGenerator");
String str = "hello world jackson!";
jsonGenerator.writeBinary(str.getBytes());
jsonGenerator.writeBoolean(true);
jsonGenerator.writeNull();
jsonGenerator.writeNumber(2.2f);
jsonGenerator.writeRaw("c");
jsonGenerator.writeRaw(str, 5, 10);
jsonGenerator.writeRawValue(str, 5, 5);
jsonGenerator.writeString(str);
jsonGenerator.writeTree(JsonNodeFactory.instance.POJONode(str));
System.out.println();
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");
//complex Object
jsonGenerator.writeStartObject();//{
jsonGenerator.writeObjectField("user", bean);//user:{bean}
jsonGenerator.writeObjectField("infos", arr);//infos:[array]
jsonGenerator.writeEndObject();//}
} catch (Exception e) {
e.printStackTrace();
}}运行后，结果如下：jsonGenerator"aGVsbG8gd29ybGQgamFja3NvbiE=" true null 2.2c world jac
worl "hello world jackson!" "hello world jackson!" {"user":{"name":"jackson","sex":true,"age":22},"infos":[22,"this is array"]} {"user":{"address":"address","name":"haha","id":1,"birthday":null,"email":"email"},"infos":["a","b","c"]}怎么样？构造的json字符串和输出的结果是一致的吧。关键看懂用JSONGenerator提供的方法，完成一个Object的构建。三、JSON转换成Java对象1、 将json字符串转换成JavaBean对象@Testpublic void readJson2Entity() {
String json = "{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}";
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();
}}很简单，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，第二个参数是即将将这个JSON解析吃什么Java对象，Java对象的类型。当然，还有其他相同签名方法，如果你有兴趣可以一一尝试使用方法，当然使用的方法和当前使用的方法大同小异。运行后，结果如下：hahahaha#1#address#null#email2、 将json字符串转换成List&Map&集合/** * &b&function:&/b&json字符串转换成list&map& * @author hoojo * @createDate
下午06:12:01 */@Testpublic void readJson2List() {
String json = "[{\"address\": \"address2\",\"name\":\"haha2\",\"id\":2,\"email\":\"email2\"},"+
"{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}]";
List&LinkedHashMap&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&String& it = set.iterator();it.hasNext();) {
String key = it.next();
System.out.println(key + ":" + map.get(key));
} catch (JsonParseException e) {
e.printStackTrace();
} catch (JsonMappingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}}尝试过将上面的JSON转换成List，然后List中存放AccountBean，但结果失败了。但是支持Map集合。因为你转成List.class，但是不知道List存放何种类型。只好默然Map类型。因为所有的对象都可以转换成Map结合，运行后结果如下：2address:address2name:haha2id:2email:email2address:addressname:hahaid:1email:email3、 Json字符串转换成Array数组，由于上面的泛型转换不能识别到集合中的对象类型。所有这里用对象数组，可以解决这个问题。只不过它不再是集合，而是一个数组。当然这个不重要，你可以用Arrays.asList将其转换成List即可。/** * &b&function:&/b&json字符串转换成Array * @author hoojo * @createDate
下午06:14:01 */@Testpublic void readJson2Array() {
String json = "[{\"address\": \"address2\",\"name\":\"haha2\",\"id\":2,\"email\":\"email2\"},"+
"{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}]";
AccountBean[] arr = objectMapper.readValue(json, AccountBean[].class);
System.out.println(arr.length);
for (int i = 0; i & arr. i++) {
System.out.println(arr[i]);
} catch (JsonParseException e) {
e.printStackTrace();
} catch (JsonMappingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}}运行后的结果：2haha2#2#address2#null#email2haha#1#address#null#email4、 Json字符串转换成Map集合/** * &b&function:&/b&json字符串转换Map集合 * @author hoojo * @createDate Nov 27, :06 PM */@Testpublic void readJson2Map() {
String json = "{\"success\":true,\"A\":{\"address\": \"address2\",\"name\":\"haha2\",\"id\":2,\"email\":\"email2\"},"+
"\"B\":{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}}";
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();
}}运行后结果如下：3success:trueA:{address=address2, name=haha2, id=2, email=email2}B:{address=address, name=haha, id=1, email=email}四、Jackson对XML的支持Jackson也可以完成java对象到xml的转换，转换后的结果要比json-lib更直观，不过它依赖于stax2-api.jar这个jar包。/** * &b&function:&/b&java对象转换成xml文档 * 需要额外的jar包 stax2-api.jar * @author hoojo * @createDate
下午06:11:21 */@Testpublic void writeObject2Xml() {
//stax2-api-3.0.2.jar
System.out.println("XmlMapper");
XmlMapper xml = new XmlMapper();
//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);
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);
map.put("B", bean);
System.out.println(xml.writeValueAsString(map));
} catch (JsonGenerationException e) {
e.printStackTrace();
} catch (JsonMappingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}}运行上面的方法，结果如下：XmlMapper&unknown&&address&china-Guangzhou&/address&&name&hoojo&/name&&id&1&/id&&birthday/&&email&hoojo_@&/email&&/unknown&&unknown&&unknown&&address&china-Guangzhou&/address&&name&hoojo&/name&&id&1&/id&&birthday/&&email&hoojo_@&/email&&/unknown&&email&&address&china-Guangzhou&/address&&name&hoojo&/name&&id&1&/id&&birthday/&&email&hoojo_@&/email&&/email&&/unknown&&unknown&&A&&address&china-Guangzhou&/address&&name&hoojo&/name&&id&1&/id&&birthday/&&email&hoojo_@&/email&&/A&&B&&address&china-Guangzhou&/address&&name&hoojo&/name&&id&1&/id&&birthday/&&email&hoojo_@&/email&&/B&&/unknown&看结果，根节点都是unknown 这个问题还没有解决，由于根节点没有转换出来，所有导致解析xml到Java对象，也无法完成。转自：
阅读(...) 评论() &