Java_jackson_bean/map/list与json相互转换-蒲公英云

Java_jackson_bean/map/list与json相互转换

1. 下载(免积分)

json_jackson_junit_demo.zip

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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}
    }
}