如何使用Java读取Android属性

Question

我在终端中使用'adb shell getprop'.我可以在Android JAVA中使用哪些接口来获取相同的信息？

我尝试过几样的事情:

Properties sysProps = System.getProperties();

但我不认为这些是我想要的相同属性？具体来说,我想找到将返回类似于以下内容的值:

adb shell getprop | grep dolby

shell'grep dolby'命令返回:

[audio.dolby.ds2.enabled]: [true] 
[dolby.audio.sink.info]: [headset] 
[dolby.ds.dialogenhancer.state]: [on] 
[dolby.ds.graphiceq.state]: [off] 
[dolby.ds.hpvirtualizer.state]: [off] 
[dolby.ds.intelligenteq.preset]: [Off] 
[dolby.ds.intelligenteq.state]: [off] 
[dolby.ds.platform]: [qcom] 
[dolby.ds.profile.name]: [Movie] 
[dolby.ds.spkvirtualizer.state]: [off] 
[dolby.ds.state]: [off] 
[dolby.ds.volumeleveler.state]: [on] 

但我想在Android JAVA代码中访问此信息.

有任何想法吗？

Answer 1

实际上有一个系统端的调用实现getprop。它被称为并可以在这里Systemproperties.get()找到。对于在 AOSP 内部处理系统代码的用户，或者确实想要冒险使用 的用户，这是正确的选择。reflect

Answer 2

System.getProperties() 不会返回与 getprop 相同的属性。

要获取 getprop 属性，请尝试使用 Runtime.exec() 执行 getprop 并读取其标准输出。

Answer 3

万一有人想知道我的解决方案...在乔治的帮助下，我最终使用了这个：

private String propReader() {
        Process process = null;
        try {
            process = new ProcessBuilder().command("/system/bin/getprop")
                    .redirectErrorStream(true).start();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        InputStream in = process.getInputStream();

        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));

        StringBuilder log = new StringBuilder();
        String line;
        try {
            while ((line = bufferedReader.readLine()) != null) {
                if (line.contains("dolby"))
                    log.append(line + "\n");
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        System.out.println(in);

        process.destroy();
        return log.toString();
    }

Answer 4

我清理了TMont的解决方案，并使其更加通用（为propertyName添加了参数）：

import android.util.Log;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class SystemProperties {

    private static String GETPROP_EXECUTABLE_PATH = "/system/bin/getprop";
    private static String TAG = "MyApp";

    public static String read(String propName) {
        Process process = null;
        BufferedReader bufferedReader = null;

        try {
            process = new ProcessBuilder().command(GETPROP_EXECUTABLE_PATH, propName).redirectErrorStream(true).start();
            bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
            String line = bufferedReader.readLine();
            if (line == null){
                line = ""; //prop not set
            }
            Log.i(TAG,"read System Property: " + propName + "=" + line);
            return line;
        } catch (Exception e) {
            Log.e(TAG,"Failed to read System Property " + propName,e);
            return "";
        } finally{
            if (bufferedReader != null){
                try {
                    bufferedReader.close();
                } catch (IOException e) {}
            }
            if (process != null){
                process.destroy();
            }
        }
    }
}