java String packageName = intent.getDataString(); 怎么只取包名

您可以使用Java中的URI类和PackageManager类来获取包名。

您可以尝试以下代码：

Uri uri = Uri.parse(packageName);
String packageNameOnly = uri.getSchemeSpecificPart();
PackageManager packageManager = context.getPackageManager();
PackageInfo packageInfo = packageManager.getPackageInfo(packageNameOnly, 0);
String packageName = packageInfo.packageName;

这里，我们首先将intent.getDataString()返回的字符串转换为Uri对象，然后使用getSchemeSpecificPart()方法从Uri对象中提取包名。接着，我们使用PackageManager类通过包名获取PackageInfo对象，最后从PackageInfo对象中获取包名。

请注意，这段代码需要在try-catch块中执行，以处理可能的异常。

相关问题

java String packageName = intent.getDataString(); if (packageName != null) { // 目标应用被关闭了，执行自己的逻辑 // ... for (int i=0;i<handlerManager.get_BrowsableApkInfo().getJSONArray("content_list").size();i++){ } }补全是否packageName是否在json中

以下是补全后的代码，判断 `packageName` 是否在 JSON 中：

java
String packageName = intent.getDataString();
if (packageName != null) {
    // 目标应用被关闭了，执行自己的逻辑
    // ...
    JSONArray contentList = handlerManager.get_BrowsableApkInfo().getJSONArray("content_list");
    boolean isPackageExist = false;
    for (int i = 0; i < contentList.size(); i++) {
        JSONObject content = contentList.getJSONObject(i);
        String packageNameInJson = content.getString("package_name");
        if (packageName.equals(packageNameInJson)) {
            isPackageExist = true;
            break;
        }
    }
    if (isPackageExist) {
        // packageName 存在于 JSON 中
        // ...
    } else {
        // packageName 不存在于 JSON 中
        // ...
    }
}

优化代码public class SecondActivity extends AppCompatActivity { private TextView textView9, textView11, textView13, textView15, textView17, textView19; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_second); Intent intent = getIntent(); String num = intent.getStringExtra("num"); String name = intent.getStringExtra("name"); String score1 = intent.getStringExtra("score1"); String score2 = intent.getStringExtra("score2"); String score3 = intent.getStringExtra("score3"); double average = intent.getDoubleExtra("average", 0); textView9 = findViewById(R.id.textView9); textView11 = findViewById(R.id.textView11); textView13 = findViewById(R.id.textView13); textView15 = findViewById(R.id.textView15); textView17 = findViewById(R.id.textView17); textView19 = findViewById(R.id.textView19); textView9.setText(num); textView11.setText(name); textView13.setText(score1); textView15.setText(score2); textView17.setText(score3); textView19.setText(String.format("%.2f", average)); } }

这段代码已经非常简洁，不过还可以进一步优化：

1. 将 findViewById() 方法的调用放在 onStart() 方法中，避免在 onCreate() 方法中执行过多的操作；
2. 使用 ButterKnife 或者 ViewBinding 来代替 findViewById() 方法，可以进一步简化代码。

下面是使用 ButterKnife 优化后的代码：

public class SecondActivity extends AppCompatActivity {
    @BindView(R.id.textView9)
    TextView textView9;
    @BindView(R.id.textView11)
    TextView textView11;
    @BindView(R.id.textView13)
    TextView textView13;
    @BindView(R.id.textView15)
    TextView textView15;
    @BindView(R.id.textView17)
    TextView textView17;
    @BindView(R.id.textView19)
    TextView textView19;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        ButterKnife.bind(this);

        Intent intent = getIntent();
        String num = intent.getStringExtra("num");
        String name = intent.getStringExtra("name");
        String score1 = intent.getStringExtra("score1");
        String score2 = intent.getStringExtra("score2");
        String score3 = intent.getStringExtra("score3");
        double average = intent.getDoubleExtra("average", 0);

        textView9.setText(num);
        textView11.setText(name);
        textView13.setText(score1);
        textView15.setText(score2);
        textView17.setText(score3);
        textView19.setText(String.format("%.2f", average));
    }
}

使用 ViewBinding 优化后的代码：

public class SecondActivity extends AppCompatActivity {
    private ActivitySecondBinding binding;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivitySecondBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());

        Intent intent = getIntent();
        String num = intent.getStringExtra("num");
        String name = intent.getStringExtra("name");
        String score1 = intent.getStringExtra("score1");
        String score2 = intent.getStringExtra("score2");
        String score3 = intent.getStringExtra("score3");
        double average = intent.getDoubleExtra("average", 0);

        binding.textView9.setText(num);
        binding.textView11.setText(name);
        binding.textView13.setText(score1);
        binding.textView15.setText(score2);
        binding.textView17.setText(score3);
        binding.textView19.setText(String.format("%.2f", average));
    }
}

使用 ButterKnife 或者 ViewBinding 可以使代码更加简洁易读。