一万年来谁著史，三千里外欲封侯。这篇文章主要讲述android快速开发--常用utils类相关的知识，希望能为你提供帮助。
1、日志工具类L.java

package com.zhy.utils; import android.util.Log; /** * Log统一管理类 * * * */ public class L {private L() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); }public static boolean isDebug = true; // 是否需要打印bug，可以在application的onCreate函数里面初始化 private static final String TAG = "way"; // 下面四个是默认tag的函数 public static void i(String msg) { if (isDebug) Log.i(TAG, msg); }public static void d(String msg) { if (isDebug) Log.d(TAG, msg); }public static void e(String msg) { if (isDebug) Log.e(TAG, msg); }public static void v(String msg) { if (isDebug) Log.v(TAG, msg); }// 下面是传入自定义tag的函数 public static void i(String tag, String msg) { if (isDebug) Log.i(tag, msg); }public static void d(String tag, String msg) { if (isDebug) Log.i(tag, msg); }public static void e(String tag, String msg) { if (isDebug) Log.i(tag, msg); }public static void v(String tag, String msg) { if (isDebug) Log.i(tag, msg); } }

网上看到的类，注释上应该原创作者的名字，很简单的一个类；网上也有很多提供把日志记录到SDCard上的，不过我是从来没记录过，所以引入个最简单的，大家可以进行评价是否需要扩充~~
2、Toast统一管理类 

package com.zhy.utils; import android.content.Context; import android.widget.Toast; /** * Toast统一管理类 * */ public class T {private T() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); }public static boolean isShow = true; /** * 短时间显示Toast * * @param context * @param message */ public static void showShort(Context context, CharSequence message) { if (isShow) Toast.makeText(context, message, Toast.LENGTH_SHORT).show(); }/** * 短时间显示Toast * * @param context * @param message */ public static void showShort(Context context, int message) { if (isShow) Toast.makeText(context, message, Toast.LENGTH_SHORT).show(); }/** * 长时间显示Toast * * @param context * @param message */ public static void showLong(Context context, CharSequence message) { if (isShow) Toast.makeText(context, message, Toast.LENGTH_LONG).show(); }/** * 长时间显示Toast * * @param context * @param message */ public static void showLong(Context context, int message) { if (isShow) Toast.makeText(context, message, Toast.LENGTH_LONG).show(); }/** * 自定义显示Toast时间 * * @param context * @param message * @param duration */ public static void show(Context context, CharSequence message, int duration) { if (isShow) Toast.makeText(context, message, duration).show(); }/** * 自定义显示Toast时间 * * @param context * @param message * @param duration */ public static void show(Context context, int message, int duration) { if (isShow) Toast.makeText(context, message, duration).show(); }}

也是非常简单的一个封装，能省则省了~~
3、SharedPreferences封装类SPUtils

package com.zhy.utils; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.util.Map; import android.content.Context; import android.content.SharedPreferences; public class SPUtils { /** * 保存在手机里面的文件名 */ public static final String FILE_NAME = "share_data"; /** * 保存数据的方法，我们需要拿到保存数据的具体类型，然后根据类型调用不同的保存方法 * * @param context * @param key * @param object */ public static void put(Context context, String key, Object object) {SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); SharedPreferences.Editor editor = sp.edit(); if (object instanceof String) { editor.putString(key, (String) object); } else if (object instanceof Integer) { editor.putInt(key, (Integer) object); } else if (object instanceof Boolean) { editor.putBoolean(key, (Boolean) object); } else if (object instanceof Float) { editor.putFloat(key, (Float) object); } else if (object instanceof Long) { editor.putLong(key, (Long) object); } else { editor.putString(key, object.toString()); }SharedPreferencesCompat.apply(editor); }/** * 得到保存数据的方法，我们根据默认值得到保存的数据的具体类型，然后调用相对于的方法获取值 * * @param context * @param key * @param defaultObject * @return */ public static Object get(Context context, String key, Object defaultObject) { SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); if (defaultObject instanceof String) { return sp.getString(key, (String) defaultObject); } else if (defaultObject instanceof Integer) { return sp.getInt(key, (Integer) defaultObject); } else if (defaultObject instanceof Boolean) { return sp.getBoolean(key, (Boolean) defaultObject); } else if (defaultObject instanceof Float) { return sp.getFloat(key, (Float) defaultObject); } else if (defaultObject instanceof Long) { return sp.getLong(key, (Long) defaultObject); }return null; }/** * 移除某个key值已经对应的值 * @param context * @param key */ public static void remove(Context context, String key) { SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); SharedPreferences.Editor editor = sp.edit(); editor.remove(key); SharedPreferencesCompat.apply(editor); }/** * 清除所有数据 * @param context */ public static void clear(Context context) { SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); SharedPreferences.Editor editor = sp.edit(); editor.clear(); SharedPreferencesCompat.apply(editor); }/** * 查询某个key是否已经存在 * @param context * @param key * @return */ public static boolean contains(Context context, String key) { SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); return sp.contains(key); }/** * 返回所有的键值对 * * @param context * @return */ public static Map< String, ?> getAll(Context context) { SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); return sp.getAll(); }/** * 创建一个解决SharedPreferencesCompat.apply方法的一个兼容类 * * @author zhy * */ private static class SharedPreferencesCompat { private static final Method sApplyMethod = findApplyMethod(); /** * 反射查找apply的方法 * * @return */ @SuppressWarnings({ "unchecked", "rawtypes" }) private static Method findApplyMethod() { try { Class clz = SharedPreferences.Editor.class; return clz.getMethod("apply"); } catch (NoSuchMethodException e) { }return null; }/** * 如果找到则使用apply执行，否则使用commit * * @param editor */ public static void apply(SharedPreferences.Editor editor) { try { if (sApplyMethod != null) { sApplyMethod.invoke(editor); return; } } catch (IllegalArgumentException e) { } catch (IllegalAccessException e) { } catch (InvocationTargetException e) { } editor.commit(); } }}

对SharedPreference的使用做了建议的封装，对外公布出put，get，remove，clear等等方法；
 
注意一点，里面所有的commit操作使用了SharedPreferencesCompat.apply进行了替代，目的是尽可能的使用apply代替commit
首先说下为什么，因为commit方法是同步的，并且我们很多时候的commit操作都是UI线程中，毕竟是IO操作，尽可能异步；
所以我们使用apply进行替代，apply异步的进行写入；
但是apply相当于commit来说是new API呢，为了更好的兼容，我们做了适配；
SharedPreferencesCompat也可以给大家创建兼容类提供了一定的参考~~
4、单位转换类  DensityUtils

package com.zhy.utils; import android.content.Context; import android.util.TypedValue; /** * 常用单位转换的辅助类 * * * */ public class DensityUtils { private DensityUtils() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); }/** * dp转px * * @param context * @param val * @return */ public static int dp2px(Context context, float dpVal) { return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dpVal, context.getResources().getDisplayMetrics()); }/** * sp转px * * @param context * @param val * @return */ public static int sp2px(Context context, float spVal) { return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, spVal, context.getResources().getDisplayMetrics()); }/** * px转dp * * @param context * @param pxVal * @return */ public static float px2dp(Context context, float pxVal) { final float scale = context.getResources().getDisplayMetrics().density; return (pxVal / scale); }/** * px转sp * * @param fontScale * @param pxVal * @return */ public static float px2sp(Context context, float pxVal) { return (pxVal / context.getResources().getDisplayMetrics().scaledDensity); }}

5、SD卡相关辅助类  SDCardUtils

package com.zhy.utils; import java.io.File; import android.os.Environment; import android.os.StatFs; /** * SD卡相关的辅助类 * * * */ public class SDCardUtils { private SDCardUtils() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); }/** * 判断SDCard是否可用 * * @return */ public static boolean isSDCardEnable() { return Environment.getExternalStorageState().equals( Environment.MEDIA_MOUNTED); }/** * 获取SD卡路径 * * @return */ public static String getSDCardPath() { return Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator; }/** * 获取SD卡的剩余容量 单位byte * * @return */ public static long getSDCardAllSize() { if (isSDCardEnable()) { StatFs stat = new StatFs(getSDCardPath()); // 获取空闲的数据块的数量 long availableBlocks = (long) stat.getAvailableBlocks() - 4; // 获取单个数据块的大小（byte） long freeBlocks = stat.getAvailableBlocks(); return freeBlocks * availableBlocks; } return 0; }/** * 获取指定路径所在空间的剩余可用容量字节数，单位byte * * @param filePath * @return 容量字节 SDCard可用空间，内部存储可用空间 */ public static long getFreeBytes(String filePath) { // 如果是sd卡的下的路径，则获取sd卡可用容量 if (filePath.startsWith(getSDCardPath())) { filePath = getSDCardPath(); } else {// 如果是内部存储的路径，则获取内存存储的可用容量 filePath = Environment.getDataDirectory().getAbsolutePath(); } StatFs stat = new StatFs(filePath); long availableBlocks = (long) stat.getAvailableBlocks() - 4; return stat.getBlockSize() * availableBlocks; }/** * 获取系统存储路径 * * @return */ public static String getRootDirectoryPath() { return Environment.getRootDirectory().getAbsolutePath(); }}

6、屏幕相关辅助类  ScreenUtils

package com.zhy.utils; import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Rect; import android.util.DisplayMetrics; import android.view.View; import android.view.WindowManager; /** * 获得屏幕相关的辅助类 * * * */ public class ScreenUtils { private ScreenUtils() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); }/** * 获得屏幕高度 * * @param context * @return */ public static int getScreenWidth(Context context) { WindowManager wm = (WindowManager) context .getSystemService(Context.WINDOW_SERVICE); DisplayMetrics outMetrics = new DisplayMetrics(); wm.getDefaultDisplay().getMetrics(outMetrics); return outMetrics.widthPixels; }/** * 获得屏幕宽度 * * @param context * @return */ public static int getScreenHeight(Context context) { WindowManager wm = (WindowManager) context .getSystemService(Context.WINDOW_SERVICE); DisplayMetrics outMetrics = new DisplayMetrics(); wm.getDefaultDisplay().getMetrics(outMetrics); return outMetrics.heightPixels; }/** * 获得状态栏的高度 * * @param context * @return */ public static int getStatusHeight(Context context) {int statusHeight = -1; try { Class< ?> clazz = Class.forName("com.android.internal.R$dimen"); Object object = clazz.newInstance(); int height = Integer.parseInt(clazz.getField("status_bar_height") .get(object).toString()); statusHeight = context.getResources().getDimensionPixelSize(height); } catch (Exception e) { e.printStackTrace(); } return statusHeight; }/** * 获取当前屏幕截图，包含状态栏 * * @param activity * @return */ public static Bitmap snapShotWithStatusBar(Activity activity) { View view = activity.getWindow().getDecorView(); view.setDrawingCacheEnabled(true); view.buildDrawingCache(); Bitmap bmp = view.getDrawingCache(); int width = getScreenWidth(activity); int height = getScreenHeight(activity); Bitmap bp = null; bp = Bitmap.createBitmap(bmp, 0, 0, width, height); view.destroyDrawingCache(); return bp; }/** * 获取当前屏幕截图，不包含状态栏 * * @param activity * @return */ public static Bitmap snapShotWithoutStatusBar(Activity activity) { View view = activity.getWindow().getDecorView(); view.setDrawingCacheEnabled(true); view.buildDrawingCache(); Bitmap bmp = view.getDrawingCache(); Rect frame = new Rect(); activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame); int statusBarHeight = frame.top; int width = getScreenWidth(activity); int height = getScreenHeight(activity); Bitmap bp = null; bp = Bitmap.createBitmap(bmp, 0, statusBarHeight, width, height - statusBarHeight); view.destroyDrawingCache(); return bp; }}

7、App相关辅助类

package com.zhy.utils; import android.content.Context; import android.content.pm.PackageInfo; import android.content.pm.PackageManager; import android.content.pm.PackageManager.NameNotFoundException; /** * 跟App相关的辅助类 * * * */ public class AppUtils {private AppUtils() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); }/** * 获取应用程序名称 */ public static String getAppName(Context context) { try { PackageManager packageManager = context.getPackageManager(); PackageInfo packageInfo = packageManager.getPackageInfo( context.getPackageName(), 0); int labelRes = packageInfo.applicationInfo.labelRes; return context.getResources().getString(labelRes); } catch (NameNotFoundException e) { e.printStackTrace(); } return null; }/** * [获取应用程序版本名称信息] * * @param context * @return 当前应用的版本名称 */ public static String getVersionName(Context context) { try { PackageManager packageManager = context.getPackageManager(); PackageInfo packageInfo = packageManager.getPackageInfo( context.getPackageName(), 0); return packageInfo.versionName; } catch (NameNotFoundException e) { e.printStackTrace(); } return null; }}

8、软键盘相关辅助类KeyBoardUtils

package com.zhy.utils; import android.content.Context; import android.view.inputmethod.InputMethodManager; import android.widget.EditText; /** * 打开或关闭软键盘 * * @author zhy * */ public class KeyBoardUtils { /** * 打卡软键盘 * * @param mEditText *输入框 * @param mContext *上下文 */ public static void openKeybord(EditText mEditText, Context mContext) { InputMethodManager imm = (InputMethodManager) mContext .getSystemService(Context.INPUT_METHOD_SERVICE); imm.showSoftInput(mEditText, InputMethodManager.RESULT_SHOWN); imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, InputMethodManager.HIDE_IMPLICIT_ONLY); }/** * 关闭软键盘 * * @param mEditText *输入框 * @param mContext *上下文 */ public static void closeKeybord(EditText mEditText, Context mContext) { InputMethodManager imm = (InputMethodManager) mContext .getSystemService(Context.INPUT_METHOD_SERVICE); imm.hideSoftInputFromWindow(mEditText.getWindowToken(), 0); } }

9、网络相关辅助类  NetUtils

package com.zhy.utils; import android.app.Activity; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.net.ConnectivityManager; import android.net.NetworkInfo; /** * 跟网络相关的工具类 * * * */ public class NetUtils { private NetUtils() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); }/** * 判断网络是否连接 * * @param context * @return */ public static boolean isConnected(Context context) {ConnectivityManager connectivity = (ConnectivityManager) context .getSystemService(Context.CONNECTIVITY_SERVICE); if (null != connectivity) {NetworkInfo info = connectivity.getActiveNetworkInfo(); if (null != info & & info.isConnected()) { if (info.getState() == NetworkInfo.State.CONNECTED) { return true; } } } return false; }/** * 判断是否是wifi连接 */ public static boolean isWifi(Context context) { ConnectivityManager cm = (ConnectivityManager) context .getSystemService(Context.CONNECTIVITY_SERVICE); if (cm == null) return false; return cm.getActiveNetworkInfo().getType() == ConnectivityManager.TYPE_WIFI; }/** * 打开网络设置界面 */ public static void openSetting(Activity activity) { Intent intent = new Intent("/"); ComponentName cm = new ComponentName("com.android.settings", "com.android.settings.WirelessSettings"); intent.setComponent(cm); intent.setAction("android.intent.action.VIEW"); activity.startActivityForResult(intent, 0); }}

10、Http相关辅助类  HttpUtils

package com.zhy.utils; import java.io.BufferedReader; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.PrintWriter; import java.net.HttpURLConnection; import java.net.URL; /** * Http请求的工具类 * * @author zhy * */ public class HttpUtils {private static final int TIMEOUT_IN_MILLIONS = 5000; public interface CallBack { void onRequestComplete(String result); }/** * 异步的Get请求 * * @param urlStr * @param callBack */ public static void doGetAsyn(final String urlStr, final CallBack callBack) { new Thread() { public void run() { try { String result = doGet(urlStr); if (callBack != null) { callBack.onRequestComplete(result); } } catch (Exception e) { e.printStackTrace(); }}; }.start(); }/** * 异步的Post请求 * @param urlStr * @param params * @param callBack * @throws Exception */ public static void doPostAsyn(final String urlStr, final String params, final CallBack callBack) throws Exception { new Thread() { public void run() { try { String result = doPost(urlStr, params); if (callBack != null) { callBack.onRequestComplete(result); } } catch (Exception e) { e.printStackTrace(); }}; }.start(); }/** * Get请求，获得返回数据 * * @param urlStr * @return * @throws Exception */ public static String doGet(String urlStr) { URL url = null; HttpURLConnection conn = null; InputStream is = null; ByteArrayOutputStream baos = null; try { url = new URL(urlStr); conn = (HttpURLConnection) url.openConnection(); conn.setReadTimeout(TIMEOUT_IN_MILLIONS); conn.setConnectTimeout(TIMEOUT_IN_MILLIONS); conn.setRequestMethod("GET"); conn.setRequestProperty("accept", "*/*"); conn.setRequestProperty("connection", "Keep-Alive"); if (conn.getResponseCode() == 200) { is = conn.getInputStream(); baos = new ByteArrayOutputStream(); int len = -1; byte[] buf = new byte[128]; while ((len = is.read(buf)) != -1) { baos.write(buf, 0, len); } baos.flush(); return baos.toString(); } else { throw new RuntimeException(" responseCode is not 200 ... "); }} catch (Exception e) { e.printStackTrace(); } finally { try { if (is != null) is.close(); } catch (IOException e) { } try { if (baos != null) baos.close(); } catch (IOException e) { } conn.disconnect(); }return null ; }/** * 向指定 URL 发送POST方法的请求 * * @param url *发送请求的 URL * @param param *请求参数，请求参数应该是 name1=value1& name2=value2 的形式。 * @return 所代表远程资源的响应结果 * @throws Exception */ public static String doPost(String url, String param) { PrintWriter out = null; BufferedReader in = null; String result = ""; try { URL realUrl = new URL(url); // 打开和URL之间的连接 HttpURLConnection conn = (HttpURLConnection) realUrl .openConnection(); // 设置通用的请求属性 conn.setRequestProperty("accept", "*/*"); conn.setRequestProperty("connection", "Keep-Alive"); conn.setRequestMethod("POST"); conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); conn.setRequestProperty("charset", "utf-8"); conn.setUseCaches(false); // 发送POST请求必须设置如下两行 conn.setDoOutput(true); conn.setDoInput(true); conn.setReadTimeout(TIMEOUT_IN_MILLIONS); conn.setConnectTimeout(TIMEOUT_IN_MILLIONS); if (param != null & & !param.trim().equals("")) { // 获取URLConnection对象对应的输出流 out = new PrintWriter(conn.getOutputStream()); // 发送请求参数 out.print(param); // flush输出流的缓冲 out.flush(); } // 定义BufferedReader输入流来读取URL的响应 in = new BufferedReader( new InputStreamReader(conn.getInputStream())); String line; while ((line = in.readLine()) != null) { result += line; } } catch (Exception e) { e.printStackTrace(); } // 使用finally块来关闭输出流、输入流 finally { try { if (out != null) { out.close(); } if (in != null) { in.close(); } } catch (IOException ex) { ex.printStackTrace(); } } return result; } }

【android快速开发--常用utils类】 

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