JSON解析使用JSONObject.keys()可以获取所有的key值，但是这种方法只能获取一层：
比如{"b":"2","c":{"A":"1","B":"2"},"a":"1"}，只能够获取b,c,a
如果想要获取被嵌套的{"A":"1","B":"2"}中A,B就不可以了
自己实现了一下获取嵌套类型的JSONObject的所有key值
import java.util.Iterator;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class testGetKeys {
public static String getKeys(JSONObject test) throws JSONException{
String result = null;
testJsonCompare t = new testJsonCompare();
Iterator keys = test.keys();
while(keys.hasNext()){
try{
String key = keys.next().toString();
String value = test.optString(key);
int i = t.testIsArrayORObject(value);
if(result == null || result.equals("")){
if(i == 0){
result = key + ",";
System.out.println("i=0 | key="+key+"| result="+result);
}else if( i == 1){
result = key + ",";
System.out.println("i=1 | key="+key+"| result="+result);
result = getKeys(new JSONObject(value))+",";
}else if( i == 2){
result = key + ",";
System.out.println("i=2 | key="+key+"| result="+result);
JSONArray arrays = new JSONArray(value);
for(int k =0;k<arrays.length();k++){
JSONObject array = new JSONObject(arrays.get(k));
result = getKeys(array) + ",";
}
}
}else{
if(i == 0){
result = result + key + ",";
System.out.println("i=0 | key="+key+"| result="+result);
}else if( i == 1){
result = result + key + ",";
System.out.println("i=1 | key="+key+"| result="+result);
result = result + getKeys(new JSONObject(value));
}else if( i == 2){
result = result + key + ",";
System.out.println("i=2 | key="+key+"| result="+result);
JSONArray arrays = new JSONArray(value);
for(int k =0;k<arrays.length();k++){
JSONObject array = new JSONObject(arrays.get(k));
result = result + getKeys(array) + ",";
}
}
}
}catch(JSONException e){
e.printStackTrace();
}
}
return result;
}
public static void main(String args[]) throws org.json.JSONException{
JSONObject test = new JSONObject();
JSONObject test1 = new JSONObject();
try{
test1.put("A", "1");
test1.put("B", "2");
test.put("a", "1");
test.put("c", test1);
test.put("b", "2");
System.out.println(test.toString());
}catch(JSONException e){
e.printStackTrace();
}
String s = getKeys(test);
System.out.println(s);
}
}
testIsArrayORObject是判断一个字符串是array类型还是object
public int testIsArrayORObject(String sJSON){
/*
* return 0:既不是array也不是object
* return 1：是object
* return 2 ：是Array
*/
try {
JSONArray array = new JSONArray(sJSON);
return 2;
} catch (JSONException e) {// 抛错 说明JSON字符不是数组或根本就不是JSON
try {
JSONObject object = new JSONObject(sJSON);
return 1;
} catch (JSONException e2) {// 抛错 说明JSON字符根本就不是JSON
System.out.println("非法的JSON字符串");
return 0;
}
}
}