java解析Json中获取Array字段值及嵌套Json对象

1.    Json含有数组时，先把String类型的json串转换的Json对象，通过getJSONArray(key)方法获取其Array部分，然后通过下标和key获取相应子数组里具体的字段值：
String test_arrary = "{\"address\": [{\"addressLine1\": \"Noida\",\"addressLine2\": \"UP\"}],\"firstName\": \"Achyut\",\"lastName\": \"khanna\"}";

public static String getJsonArray(String reqJson) {

 

JSONObject json = null;

String address2 = null;

try {

json = new JSONObject(reqJson);

JSONArray jsonarr= json.getJSONArray("address");

String address1 = jsonarr.getJSONObject(0).getString("addressLine1");

address2 = jsonarr.getJSONObject(0).getString("addressLine2");

System.out.println("address1==" + address1);

System.out.println("address2==" + address2);

} catch (JSONException e1) {

// TODO Auto-generated catch block

e1.printStackTrace();

}

return address2;

} 

2.     获取嵌套Json值，即先获取嵌套的内层data为json对象，然后转换为string，然后可以通过getString(key)方式获取data里面的各个字段值：
String test_json = "{\"comm\":{\"comm\":null,\"data\":null,\"unitcode\":\"100001\",\"trxcode\":\"60301\",\"orderno\":\"201803050000023\",\"sendtime\":\"20180307 11:16:18\",\"sendserno\":\"20180307000000000001\",\"channel\":\"pc\",\"sendcode\":\"yxcd\",\"signcode\":\"\"},\"data\":{\"orderno\":\"201803050000023\",\"urgentflag\":null,\"loanamt\":null,\"servamt\":null,\"allamt\":\"50000.00\",\"chnsname\":\"张立男\",\"buybackreason\":null,\"filetrans\":\"0\",\"filename\":null,\"filepasswd\":null,\"filesize\":null}}";

public static String queryData(String reqJson, String data) {

String str = null;

if (null != data && !data.equals("")) {

try {

str = new JSONObject(reqJson).getJSONObject(data).toString();

} catch (JSONException e) {

e.printStackTrace();

LogUtil.info(e.getMessage());

}

} else str = "Json报文data部分为空！";

System.out.println("data ==="+str);

return str;

}