Java_jackson_bean/map/list与json相互转换

深碍√TFBOYSˉ_ 2022-08-14 01:50 196阅读 0赞

**1. 下载(免积分)**

[json\_jackson\_junit\_demo.zip][json_jackson_junit_demo.zip]

![Center][]

**2. 代码**

package org.foo.bean;
    
    public class Person {
    	
    	private String name;
    	private String gender;
    	private String age;
    	
    	// ----
    	@Override
    	public String toString() {
    		return "User{ name : \""+name+"\", gender : \""+gender+"\", age : \""+age+"\"}";
    	}
    	
    	public Person() {
    		super();
    	}
    
    	public Person(String name, String gender, String age) {
    		this.name = name;
    		this.gender = gender;
    		this.age = age;
    	}
    
    	public String getName() {
    		return name;
    	}
    	public void setName(String name) {
    		this.name = name;
    	}
    	public String getGender() {
    		return gender;
    	}
    	public void setGender(String gender) {
    		this.gender = gender;
    	}
    	public String getAge() {
    		return age;
    	}
    	public void setAge(String age) {
    		this.age = age;
    	}
    	
    	
    }

package org.foo.jackson;
    
    import java.util.ArrayList;
    import java.util.LinkedHashMap;
    import java.util.List;
    import java.util.Map;
    
    import org.codehaus.jackson.map.ObjectMapper;
    import org.codehaus.jackson.type.JavaType;
    import org.foo.bean.Person;
    import org.junit.Test;
    
    
    
    public class JsonUtils {
    	
    	private static ObjectMapper objectMapper = new ObjectMapper();
    	
    	public static <T> String bean2Json(T bean) {
    		try {
    			return objectMapper.writeValueAsString(bean);
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return "";
    	}
    	
    	public static String map2Json(Map map) {
    		try {
    			return objectMapper.writeValueAsString(map);
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return "";
    	}
    	
    	public static String list2Json(List list) {
    		try {
    			return objectMapper.writeValueAsString(list);
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return "";
    	}
    	
    	public static <T> T json2Bean(String json, Class<T> beanClass) {
    		try {
    			return objectMapper.readValue(json, beanClass);
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return null;
    	}
    	
    	public static <T> List<T> json2List(String json, Class<T> beanClass) {
    		try {
    			
    			return (List<T>)objectMapper.readValue(json, getCollectionType(List.class, beanClass));
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return null;
    	}
    	
    	public static Map json2Map(String json) {
    		try {
    			
    			return (Map)objectMapper.readValue(json, Map.class);
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return null;
    	}
    	
    	
    	public static JavaType getCollectionType(Class<?> collectionClass, Class<?>... elementClasses) {   
    		return objectMapper.getTypeFactory().constructParametricType(collectionClass, elementClasses);   
    	} 
    	
    	
    	//-------------
    	
    	@Test
    	public void testBean2Json() throws Exception{
    		Person person = new Person("张三_testBean2Json", "男", "22");
    		System.out.println( bean2Json(person) );
    		// => {"name":"张三_testBean2Json","gender":"男","age":"22"}
    	}
    	
    	@Test
    	public void testMap2Json() throws Exception{
    		
    		Map<String, String> userMap = new LinkedHashMap<String, String>();
    		userMap.put("name", "张三_testMap2Json");
    		userMap.put("gender", "男");
    		userMap.put("age", "22");
    		
    		System.out.println( map2Json(userMap) );
    		// => {"name":"张三_testMap2Json","gender":"男","age":"22"}
    	}
    	
    	@Test
    	public void testList2Json() throws Exception{
    		
    		List<String> list = new ArrayList<String>();
    		list.add("张三_testList2Json");
    		list.add("男");
    		list.add("22");
    		
    		System.out.println( list2Json(list) );
    		// => ["张三_testList2Json","男","22"]
    		
    		List<Person> personList = new ArrayList<Person>();
    		personList.add( new Person("张1", "男1", "11") );
    		personList.add( new Person("张2", "男2", "22") );
    		
    		System.out.println( list2Json(personList) );
    		// => [{"name":"张1","age":"11","gender":"男1"},{"name":"张2","age":"22","gender":"男2"}]
    	}
    	
    	@Test
    	public void testJson2Bean() throws Exception{
    		Person person = new Person("张三_testJson2Bean", "男", "22");
    		String json = bean2Json(person);
    		System.out.println( json2Bean(json, Person.class) );
    		// => User{ name : "张三_testJson2Bean", gender : "男", age : "22"}
    		
    		json = "{\"name\":\"wahh\"}";
    		System.out.println( json2Bean(json, Person.class) );
    	}
    	
    	@Test
    	public void testJson2List() throws Exception{
    		Person person1 = new Person("张三1", "男1", "11");
    		Person person2 = new Person("张三2", "男2", "22");
    		List<Person> personList = new ArrayList<Person>();
    		personList.add(person1);
    		personList.add(person2);
    		
    		System.out.println( json2List( list2Json(personList) , Person.class) );
    		// => [User{ name : "张三1", gender : "男1", age : "11"}, User{ name : "张三2", gender : "男2", age : "22"}]
    	}
    	
    	@Test
    	public void testJson2Map() throws Exception{
    		Person person = new Person("张三", "男", "22");
    		String json = bean2Json(person);
    		Map map = json2Map(json);
    		System.out.println( map );
    		// => {name=张三, gender=男, age=22}
    	}
    }

[json_jackson_junit_demo.zip]: http://download.csdn.net/detail/wuqinfei_cs/8190651
[Center]: /images/20220810/88274182bc0148f088d6491461f59077.png