需要jar包：jackson-core-2.6.0.jar，jackson-databind-2.6.0.jar，jackson-annotations-2.6.0.jar
1. JSON String to Map
package com.inspur.trc.util;import java.util.HashMap;
import java.util.Map;import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;public class Json2Map {public static void main(String[] args) {String json = "{\"name\":\"zitong\", \"age\":\"26\"}";Map<String, String> map = new HashMap<String, String>();ObjectMapper mapper = new ObjectMapper();try{map = mapper.readValue(json, new TypeReference<HashMap<String,String>>(){});System.out.println(map);}catch(Exception e){e.printStackTrace();}}
}
运行结果：
{age=26, name=zitong}
2. Map to JSON String
package com.inspur.trc.util;import java.util.HashMap;
import java.util.Map;import com.fasterxml.jackson.databind.ObjectMapper;public class Map2Json {public static void main(String[] args){try{ObjectMapper mapper = new ObjectMapper();String json = "";Map<String, String> map = new HashMap<String,String>();map.put("name", "zitong");map.put("age", "26");json = mapper.writeValueAsString(map);System.out.println(json);}catch(Exception e){e.printStackTrace();}}
}
运行结果：
{"age":"26","name":"zitong"}
3. Map to JSON File
package com.inspur.trc.util;import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;import com.fasterxml.jackson.databind.ObjectMapper;public class Map2JsonFile {public static void main(String[] args) {ObjectMapper mapper = new ObjectMapper();Map<String, Object> map = new HashMap<String, Object>();map.put("name", "zitong");map.put("age", 29);List<Object> list = new ArrayList<Object>();list.add("music");list.add("football");map.put("hobby", list);try {mapper.writeValue(new File("F:/user.json"), map);} catch (Exception e) {e.printStackTrace();}}
}
运行结果：F:/user.json
{"age":29,"name":"zitong","hobby":["music","football"]}
4. JSON File To Map
package com.inspur.trc.util;import java.io.File;
import java.util.List;
import java.util.Map;import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;public class JsonFile2Map {public static void main(String[] args) {try{ObjectMapper mapper = new ObjectMapper();Map<String, Object> map = mapper.readValue(new File("F:/user.json"),new TypeReference<Map<String, Object>>(){});System.out.println("name: " + map.get("name"));System.out.println("age: " + map.get("age"));@SuppressWarnings("unchecked")List<String> list = (List<String>)map.get("hobby");System.out.print("hobby: ");for(String str : list){System.out.print(str+ " ");}}catch(Exception e){e.printStackTrace();}}
}
运行结果：
name: zitong
age: 29
hobby: music football