枫林的小窝

节选自：三种方法把文件读成一个字符串

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//Example 1
 
//Read file content into string with - Files.lines(Path path, Charset cs)
 
private static String readLineByLineJava8(String filePath)
{
    StringBuilder contentBuilder = new StringBuilder();
    try (Stream<String> stream = Files.lines( 
                                     Paths.get(filePath), StandardCharsets.UTF_8))
    {
        stream.forEach(s -> contentBuilder.append(s).append("\n"));
    }
    catch (IOException e)
    {
        e.printStackTrace();
    }
    return contentBuilder.toString();
}
 
//Example 2
 
//Read file content into string with - Files.readAllBytes(Path path)
 
private static String readAllBytesJava7(String filePath)
{
    String content = "";
    try
    {
        content = new String ( Files.readAllBytes( Paths.get(filePath) ) );
    }
    catch (IOException e)
    {
        e.printStackTrace();
    }
    return content;
}
 
//Example 3
 
//Read file content into string with - using BufferedReader and FileReader
//You can use this if you are still not using Java 8
 
private static String usingBufferedReader(String filePath)
{
    StringBuilder contentBuilder = new StringBuilder();
    try (BufferedReader br = new BufferedReader(new FileReader(filePath)))
    {
 
        String sCurrentLine;
        while ((sCurrentLine = br.readLine()) != null)
        {
            contentBuilder.append(sCurrentLine).append("\n");
        }
    }
    catch (IOException e)
    {
        e.printStackTrace();
    }
    return contentBuilder.toString();
}

节选自：libcore.io.ErrnoException: kill failed: ESRCH (No such process)

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发生崩溃的原因log里说的很清楚，就是被destroy的进程已经不存在了。

节选自：Android核心服务解析篇(三)——Android系统的启动

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RxJava 是如何实现线程切换的（上）

RxJava 是如何实现线程切换的（下）

节选自：一篇不太一样的RxJava介绍

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Observable 是一组异步数据的集合

节选自：Android 系统文件限制小探

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在Linux系统中，每个进程可以使用的FD数量是有上限的，在Android中这个上限为1024，表示每个进程可以创建的file descriptors 不能超多1024个。当系统某一文件的打开句柄数超过1024时，就会报错：

"Too many open files"

修改系统最大打开文件数量：

在init.rc中增加：
setrlimit 7 1048 1048

节选自：Eclipse中文字体大小修改

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解决方法如下：Window –> Preferences –> General –> Appearance –> Colors and Fonts，展开”Basic” 选择”Text Font”，然后点”Edit”，把大小里的值改为”五号”即可。

节选自：android 版本号大小比较

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/**
 * 版本号比较
 *
 * @param version1
 * @param version2
 * @return
 */
public static int compareVersion(String version1, String version2) {
    if (version1.equals(version2)) {
        return 0;
    }
    String[] version1Array = version1.split("\\.");
    String[] version2Array = version2.split("\\.");
    int index = 0;
    // 获取最小长度值
    int minLen = Math.min(version1Array.length, version2Array.length);
    int diff = 0;
    // 循环判断每位的大小
    while (index < minLen
            && (diff = Integer.parseInt(version1Array[index])
            - Integer.parseInt(version2Array[index])) == 0) {
        index++;
    }
    if (diff == 0) {
        // 如果位数不一致，比较多余位数
        for (int i = index; i < version1Array.length; i++) {
            if (Integer.parseInt(version1Array[i]) > 0) {
                return 1;
            }
        }

        for (int i = index; i < version2Array.length; i++) {
            if (Integer.parseInt(version2Array[i]) > 0) {
                return -1;
            }
        }
        return 0;
    } else {
        return diff > 0 ? 1 : -1;
    }
}

节选自：Android 通过apk文件获取相应的包名和版本号

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通过下面方法可以直接获取到apk的包名和版本号：apkPath是apk存放的路径

public static Drawable GetApkInfo(Context context, String apkPath) {
    PackageManager pm = context.getPackageManager();
    PackageInfo info = pm.getPackageArchiveInfo(apkPath, PackageManager.GET_ACTIVITIES);
    if (info != null) {
        ApplicationInfo appInfo = info.applicationInfo;
        String packageName = appInfo.packageName;  //得到安装包名称
        String version = info.versionName;//获取安装包的版本号
        Log.i(TAG, "getApkIcon: " + packageName + "-------" + version);
        try {
            return appInfo.loadIcon(pm);
        } catch (OutOfMemoryError e) {
            Log.i(TAG, "GetApkInfo: " + e);
        }
    }
    return null;
}