下面这个是android sdk自带的文本工具，比如提供EditText对象的内容是否为空判定，截取字符串啊等等
对外提供的方法都是以静态方法的方式提供
/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.text;
import android.content.res.Resources;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.SystemProperties;
import android.provider.Settings;
import android.text.style.AbsoluteSizeSpan;
import android.text.style.AlignmentSpan;
import android.text.style.BackgroundColorSpan;
import android.text.style.BulletSpan;
import android.text.style.CharacterStyle;
import android.text.style.EasyEditSpan;
import android.text.style.ForegroundColorSpan;
import android.text.style.LeadingMarginSpan;
import android.text.style.LocaleSpan;
import android.text.style.MetricAffectingSpan;
import android.text.style.QuoteSpan;
import android.text.style.RelativeSizeSpan;
import android.text.style.ReplacementSpan;
import android.text.style.ScaleXSpan;
import android.text.style.SpellCheckSpan;
import android.text.style.StrikethroughSpan;
import android.text.style.StyleSpan;
import android.text.style.SubscriptSpan;
import android.text.style.SuggestionRangeSpan;
import android.text.style.SuggestionSpan;
import android.text.style.SuperscriptSpan;
import android.text.style.TextAppearanceSpan;
import android.text.style.TtsSpan;
import android.text.style.TypefaceSpan;
import android.text.style.URLSpan;
import android.text.style.UnderlineSpan;
import android.util.Log;
import android.util.Printer;
import android.view.View;
import com.android.internal.R;
import com.android.internal.util.ArrayUtils;
import libcore.icu.ICU;
import java.lang.reflect.Array;
import java.util.Iterator;
import java.util.Locale;
import java.util.regex.Pattern;
public class TextUtils {
private static final String TAG = "TextUtils";
//构造函数私有，无法实例化
private TextUtils() { /* cannot be instantiated */ }
public static void getChars(CharSequence s, int start, int end,
char[] dest, int destoff) {
Class |
