java - 在android中解析简单的json字符串

Question

我想使用 json 创建一个登录和注册系统。我想首先获取 url 的内容，然后解析 json 字符串。Json 字符串示例:

{ "employee":{"mesg":"username is exsist!","id":0,"name":0,"username":0,"email":0,"status":500} }

我只需要消息或状态。我无法解析它。每次我想解析这个字符串时，我的应用程序都会强制停止

这是我的代码:

    package com.sourcey.materiallogindemo;

import android.app.ProgressDialog;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;

import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;



import butterknife.Bind;
import butterknife.ButterKnife;

public class SignupActivity extends AppCompatActivity {

    //URL to get JSON Array

    //JSON Node Names



    public String nurl;


    private static final String TAG = "SignupActivity";

    @Bind(R.id.input_name) EditText _nameText;
    @Bind(R.id.input_email) EditText _emailText;
    @Bind(R.id.input_tell) EditText _tellText;
    @Bind(R.id.input_password) EditText _passwordText;
    @Bind(R.id.btn_signup) Button _signupButton;
    @Bind(R.id.link_login) TextView _loginLink;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_signup);
        ButterKnife.bind(this);

        _signupButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                signup();
            }
        });

        _loginLink.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // Finish the registration screen and return to the Login activity
                finish();
            }
        });
    }



    public void signup() {
        Log.d(TAG, "Signup");

        if (!validate()) {
            onSignupFailed();
            return;
        }

        _signupButton.setEnabled(false);

        final ProgressDialog progressDialog = new ProgressDialog(SignupActivity.this,
                R.style.AppTheme_Dark_Dialog);
        progressDialog.setIndeterminate(true);
        progressDialog.setMessage("در حال انجام عملیات...");
        progressDialog.show();

        String name = _nameText.getText().toString();
        String email = _emailText.getText().toString();
        String tell = _tellText.getText().toString();
        String password = _passwordText.getText().toString();

        // TODO: Implement your own signup logic here.

        nurl = "http://someurl/json/user.php?type=register&mobile="+tell+"&p="+password+"&email="+email+"&name="+name;

       //new JSONParse().execute();

        new android.os.Handler().postDelayed(
                new Runnable() {
                    public void run() {

                        onSignupSuccess();
                        progressDialog.dismiss();


                    }
                }, 3000);
    }


    public void onSignupSuccess() {
        _signupButton.setEnabled(true);
        setResult(RESULT_OK, null);
        finish();
    }

    public void onSignupFailed() {
        Toast.makeText(getBaseContext(), "Login failed", Toast.LENGTH_LONG).show();

        _signupButton.setEnabled(true);
    }

    public boolean validate() {
        boolean valid = true;

        String name = _nameText.getText().toString();
        String email = _emailText.getText().toString();
        String tell = _tellText.getText().toString();
        String password = _passwordText.getText().toString();

        if (name.isEmpty() || name.length() < 3) {
            _nameText.setError("at least 3 characters");
            valid = false;
        } else {
            _nameText.setError(null);
        }

        if (email.isEmpty() || !android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
            _emailText.setError("enter a valid email address");
            valid = false;
        } else {
            _emailText.setError(null);
        }

        if (tell.isEmpty() || !android.util.Patterns.PHONE.matcher(tell).matches()) {
            _tellText.setError("enter a valid phone number");
            valid = false;
        } else {
            _tellText.setError(null);
        }

        if (password.isEmpty() || password.length() < 4 || password.length() > 10) {
            _passwordText.setError("between 4 and 10 alphanumeric characters");
            valid = false;
        } else {
            _passwordText.setError(null);
        }



        return valid;
    }













}

现在我不知道我能做什么来解析字符串并获取状态或消息，感谢 helm 。我非常需要这个，很抱歉提出这个问题。问候

Answer 1

您可以使用 JSONObject 来完成此任务。

例如(省略 try/catch):

JSONObject root = new JSONObject(jsonString);
JSONObject employee = root.getJSONObject("employee");
String message = employee.getString("name");
String username = employee.getString("username");
String email = employee.getString("email");
int id = employee.getInt("id");
int status = employee.getInt("status");

如果您不确定 JSON 的一致性，您应该 check whether the key exists首先。

您还应该检查您的 JSON 数据类型，您的姓名、用户名和电子邮件似乎都是整数。然而，这些很少是整数。

JSONObject Documentation .