在www.json.org上公布了很多Java下的json解析工具，其中org.json和json-lib比較簡單，兩者使用上差不多。下面兩段源代碼是分別使用這兩個工具解析和構造JSON的演示程序。

http://nchc.dl.sourceforge.net/sourceforge/json-lib/json-lib-2.2.1-jdk15.jar
（Needs libs below:）
[

• jakarta commons-lang 2.3
• jakarta commons-beanutils 1.7.0
• jakarta commons-collections 3.2
• jakarta commons-logging 1.1
• ezmorph 1.0.4

]
這是使用json-lib的程序：
import java.util.HashMap;
import java.util.Map;
import net.sf.json.JSONObject;
public class Test {
???? public static void main(String[] args) {
???????? String json = "{\"name\":\"reiz\"}";
???????? JSONObject jsonObj = JSONObject.fromObject(json);
???????? String name = jsonObj.getString("name");
???????? jsonObj.put("initial", name.substring(0, 1).toUpperCase());
???????? String[] likes = new String[] { "JavaScript", "Skiing", "Apple Pie" };
???????? jsonObj.put("likes", likes);
???????? Map <String, String> ingredients = new HashMap <String, String>();
???????? ingredients.put("apples", "3kg");
???????? ingredients.put("sugar", "1kg");
???????? ingredients.put("pastry", "2.4kg");
???????? ingredients.put("bestEaten", "outdoors");
???????? jsonObj.put("ingredients",ingredients);
???????? System.out.println(jsonObj);
???? }
}

http://www.json.org/java/json.zip
這是使用org.json的程序：
import java.util.HashMap;
import java.util.Map;
import org.json.JSONException;
import org.json.JSONObject;
public class Test {
???? public static void main(String[] args) throws JSONException {
???????? String json = "{\"name\":\"reiz\"}";
???????? JSONObject jsonObj = new JSONObject(json);
???????? String name = jsonObj.getString("name");
???????? jsonObj.put("initial", name.substring(0, 1).toUpperCase());
???????? String[] likes = new String[] { "JavaScript", "Skiing", "Apple Pie" };
???????? jsonObj.put("likes", likes);
???????? Map <String, String> ingredients = new HashMap <String, String>();
???????? ingredients.put("apples", "3kg");
???????? ingredients.put("sugar", "1kg");
???????? ingredients.put("pastry", "2.4kg");
???????? ingredients.put("bestEaten", "outdoors");
???????? jsonObj.put("ingredients", ingredients);
???????? System.out.println(jsonObj);
???????? System.out.println(jsonObj);
???? }
}
兩者的使用幾乎是相同的，但org.json比json-lib要輕量得多，前者沒有任何依賴，而后者要依賴ezmorph和commons的lang、logging、beanutils、collections等組件。