1、fastjson

引入包 <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.16</version> </dependency>

JSON字符串转JSONObject/JSONArray

JSONObject jsonObject = JSONObject.parseObject(jsonString); 得到子节点 jsonObject .getString(); jsonObject .getArray(); jsonObject .getDate(); ..... 转为javaBean JSONObject.toJavaObject(jsonObject,JavaBean.class); JSON字符串直接转JavaBean JSONObject.parseObject(jsonString,javaBean.class); JavaBean转JSON字符串 String jsonString = JSONObject.toJSONString(javaBean)

2、jackson

引入的包

<dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>2.8.0</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-annotations</artifactId> <version>2.8.0</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.8.0</version> </dependency>

JSON字符串装javaBean

objectMapper = new ObjectMapper(); JavaBean javaBean= objectMapper.readValue(jsonString, JavaBean.class);

javaBean转JSON字符串

objectMapper = new ObjectMapper(); //writeObject可以转换java对象，eg:JavaBean/Map/List/Array等

String jsonString = objectMapper.writeValueAsString(bean);

控制台打印：

jsonGenerator.writeObject(bean); 

//writeValue具有和writeObject相同的功能 objectMapper.writeValue(System.out, bean);

 

获取子节点

ObjectMapper mapper = new ObjectMapper();  // 读取json，将整个json作为根节点  JsonNode node = mapper.readTree(jsonString);

node.path();

node.get();

 

1. //如果属性没有值，那么Json是会处理的，int类型为0，String类型为null，数组为[]，设置这个特性可以忽略空值属性 

2. mapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);  3. //让Json可以缩进，可读性更好，一般用在测试和开发阶段。  4. mapper.configure(SerializationFeature.INDENT_OUTPUT, true);  5. //让map的key按自然顺序排列  6. mapper.configure(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS, true);  7. //日期输出格式  8. SimpleDateFormat outputFormat = new SimpleDateFormat("yyyy-MM-dd");  9. mapper.setDateFormat(outputFormat);

创建节点，生成JSON字符串

1. //创建一个提供所有节点的JsonNodeFactory,false表示不创建DecimalNode  2. JsonNodeFactory factory = new JsonNodeFactory(false);  3.  4. // 创建JsonFactory，使用Streaming API的方式输出到控制台  5. JsonFactory jsonFactory = new JsonFactory();  6. JsonGenerator generator = jsonFactory.createGenerator(System.out);  7. ObjectMapper mapper = new ObjectMapper();  8.  9. //创建节点和数据,一个ObjectNode代表一个节点对象  10. ObjectNode node1 = factory.objectNode();  11. ObjectNode node2 = factory.objectNode();  12. node1.put("A", "a");  13. node1.put("B", "b");  14. node2.set("C", node1);  15.  16. // 根节点  17. ObjectNode root = factory.objectNode();  18. root.put("root", "root");  19. root.set("children", node2);  20. mapper.writeTree(generator, root);  21. //输出{"root":"root","children":{"C":{"A":"a","B":"b"}}}

其他数组、list、map参考

http://www.cnblogs.com/hoojo/archive/2011/04/22/2024628.html http://blog.csdn.net/gjb724332682/article/details/51586701

 

3、json-lib

使用的包 <!--json-lib--> <dependency> <groupId>net.sf.json-lib</groupId> <artifactId>json-lib</artifactId> <version>2.4.0</version> </dependency> <dependency> <groupId>commons-lang</groupId> <artifactId>commons-lang</artifactId> <version>2.6</version> </dependency> <dependency> <groupId>commons-beanutils</groupId> <artifactId>commons-beanutils</artifactId> <version>1.9.2</version> </dependency> <dependency> <groupId>commons-collections</groupId> <artifactId>commons-collections</artifactId> <version>3.2.1</version> </dependency> <dependency> <groupId>commons-logging</groupId> <artifactId>commons-logging</artifactId> <version>1.2</version> </dependency> <dependency> <groupId>net.sf.ezmorph</groupId> <artifactId>ezmorph</artifactId> <version>1.0.6</version> </dependency>

JSON字符串转JSONObject/JSONArray

JSONObject jsonObject = JSONObject.fromObject(jsonString/javaBean); 得到子节点 jsonObject.getString("success") 转为javaBean JSONObject.toBean(jsonObject,JavaBean.class); javaBean转JSON字符串 String jsonString=jsonObject.toString();

list map参照

http://www.cnblogs.com/teach/p/5791029.html