Using Json-lib to convert between Java and JSON

Source: Internet
Author: User

Transfer from http://www.cnblogs.com/mailingfeng/archive/2012/01/18/2325707.html

1. Json-lib is a Java class library that provides the ability to convert Java objects, including beans, maps, collections, Java Arrays and XML, to JSON, or reverse-transform.

2. Json-lib Home: http://json-lib.sourceforge.net/

3. Execution Environment

The following class library support is required

    • Jakarta Commons-lang 2.5
    • Jakarta commons-beanutils 1.8.0
    • Jakarta commons-collections 3.2.1
    • Jakarta commons-logging 1.1.1
    • Ezmorph 1.0.6

4. Feature examples

The code example is given here through the junit-case example

Package Com.mai.json;

Import static org.junit.Assert.assertEquals;

Import java.util.ArrayList;
Import Java.util.Date;
Import Java.util.HashMap;
Import Java.util.Iterator;
Import java.util.List;
Import Java.util.Map;
Import Net.sf.ezmorph.Morpher;
Import Net.sf.ezmorph.MorpherRegistry;
Import Net.sf.ezmorph.bean.BeanMorpher;
Import Net.sf.json.JSONArray;
Import Net.sf.json.JSONObject;
Import Net.sf.json.util.JSONUtils;

Import Org.apache.commons.beanutils.PropertyUtils;
Import Org.junit.Test;

public class Jsonlibtest {

/*
* Common Type, List, collection, etc. are analyzed with Jsonarray
*
* Map, custom type is resolved with Jsonobject
* Map can be understood as an object in which the Key/value is a property/attribute value that can be understood as an object
* That is {key1:value1,key2,value2 ...}
*
* 1.JSONObject is a name:values collection, obtained by its get (key) method is the corresponding value portion of the key (string)
* Through its getjsonobject (key) can be taken to a jsonobject,--> converted into a map,
* Through its getjsonarray (key) can be taken to a jsonarray,
*
*
*/

General arrays converted to JSON
@Test
public void Testarraytojson () {
boolean[] Boolarray = new Boolean[]{true,false,true};
Jsonarray Jsonarray = Jsonarray.fromobject (Boolarray);
System.out.println (Jsonarray);
Prints [true,false,true]
}


Collection objects into JSON
@Test
public void Testlisttojson () {
List List = new ArrayList ();
List.add ("first");
List.add ("second");
Jsonarray Jsonarray = jsonarray.fromobject (list);
System.out.println (Jsonarray);
Prints ["First", "second"]
}


The string JSON is converted to JSON, as the case may be with Jsonarray or jsonobject
@Test
public void Testjsonstrtojson () {
Jsonarray Jsonarray = Jsonarray.fromobject ("[' json ', ' is ', ' easy ']");
System.out.println (Jsonarray);
Prints ["JSON", "is", "easy"]
}


The map is converted to JSON, using Jsonobject
@Test
public void Testmaptojson () {
Map map = new HashMap ();
Map.put ("name", "JSON");
Map.put ("bool", boolean.true);
Map.put ("int", new Integer (1));
Map.put ("arr", New string[]{"A", "B"});
Map.put ("func", "function (i) {return this.arr[i];}");

Jsonobject jsonobject = jsonobject.fromobject (map);
System.out.println (Jsonobject);
}

Compound type Bean turns into JSON
@Test
public void Testbeadtojson () {
Mybean bean = new Mybean ();
Bean.setid ("001");
Bean.setname ("bank card");
Bean.setdate (New Date ());

List cardnum = new ArrayList ();
Cardnum.add ("abc");
Cardnum.add ("ICBC");
Cardnum.add ("CCB");
Cardnum.add (New person ("test"));

Bean.setcardnum (Cardnum);

Jsonobject jsonobject = Jsonobject.fromobject (bean);
System.out.println (Jsonobject);

}

Normal types of JSON are converted into objects
@Test
public void Testjsontoobject () throws exception{
String json = "{name=\" json\ ", Bool:true,int:1,double:2.2,func:function (a) {return A;},array:[1,2]}";
Jsonobject Jsonobject = Jsonobject.fromobject (JSON);
System.out.println (Jsonobject);
Object bean = Jsonobject.tobean (jsonobject);
Assertequals (Jsonobject.get ("name"), Propertyutils.getproperty (Bean, "name"));
Assertequals (Jsonobject.get ("bool"), Propertyutils.getproperty (Bean, "bool"));
Assertequals (Jsonobject.get ("int"), Propertyutils.getproperty (Bean, "int"));
Assertequals (Jsonobject.get ("Double"), Propertyutils.getproperty (Bean, "double"));
Assertequals (Jsonobject.get ("func"), Propertyutils.getproperty (Bean, "func"));
System.out.println (Propertyutils.getproperty (Bean, "name"));
System.out.println (Propertyutils.getproperty (Bean, "bool"));
System.out.println (Propertyutils.getproperty (Bean, "int"));
System.out.println (Propertyutils.getproperty (Bean, "double"));
System.out.println (Propertyutils.getproperty (Bean, "func"));
System.out.println (Propertyutils.getproperty (Bean, "array"));

List arrayList = (list) jsonarray.tocollection (Jsonobject.getjsonarray ("array"));
for (Object object:arraylist) {
System.out.println (object);
}

}


Parses the JSON into a composite type object that contains the list
@Test
public void Testjsontobeanhavalist () {
String json = "{list:[{name: ' test1 '},{name: ' test2 '}],map:{test1:{name: ' test1 '},test2:{name: ' Test2 '}}";
String json = "{list:[{name: ' test1 '},{name: ' Test2 '}]}";
Map Classmap = new HashMap ();
Classmap.put ("list", Person.class);
Mybeanwithperson Diybean = (Mybeanwithperson) Jsonobject.tobean (Jsonobject.fromobject (JSON), MyBeanWithPerson.class , Classmap);
System.out.println (Diybean);

List List = Diybean.getlist ();
for (Object o:list) {
if (o instanceof person) {
Person P = (person) o;
System.out.println (P.getname ());
}
}
}


Parses the JSON into a composite type object that contains the map
@Test
public void Testjsontobeanhavamap () {
Think of map as an object
String json = "{list:[{name: ' test1 '},{name: ' test2 '}],map:{testone:{name: ' test1 '},testtwo:{name: ' Test2 '}}";
Map Classmap = new HashMap ();
Classmap.put ("list", Person.class);
Classmap.put ("Map", Map.class);
Use the hint to parse the JSON directly into the specified custom object, where list is fully parsed and map is not fully parsed
Mybeanwithperson Diybean = (Mybeanwithperson) Jsonobject.tobean (Jsonobject.fromobject (JSON), MyBeanWithPerson.class , Classmap);
System.out.println (Diybean);

System.out.println ("Do the list release");
list<person> list = Diybean.getlist ();
for (person O:list) {
Person P = (person) o;
System.out.println (P.getname ());
}

System.out.println ("Do the map release");

To register the converter in the Registrar, you need to use the class in the Ezmorph package
Morpherregistry morpherregistry = Jsonutils.getmorpherregistry ();
Morpher dynamorpher = new Beanmorpher (Person.class, morpherregistry);
Morpherregistry.registermorpher (Dynamorpher);


Map map = Diybean.getmap ();
/* There is no type hint for the map here, so by default, the object is stored as Net.sf.ezmorph.bean.MorphDynaBean type */
SYSTEM.OUT.PRINTLN (map); /* Output: {[email protected][
{Name=test1}
], [email protected][
{Name=test2}
]}      */
list<person> output = new ArrayList ();
for (Iterator i = map.values (). Iterator (); I.hasnext ();) {
Using the Registrar to transform the specified Dynabean object
Output.add (person) morpherregistry.morph (Person.class, I.next ()));
}

for (person P:output) {
System.out.println (P.getname ()); /* Output: Test1
TEST2 * *
}

}



}

5. The resources required for the above example are provided below, including the jar package and code

/files/mailingfeng/json-lib/json-lib jar Packages and Java classes required for use cases. rar

Using Json-lib to convert between Java and JSON

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