Android比较字符串是否为空(isEmpty)

StringUtils.java:

package com.yx.equipment_collection.utils;

import android.annotation.SuppressLint;
import android.text.TextUtils;
import android.util.Log;

/**
 * 
 * 此类描述的是: String帮助类
 * 
 * @author: CS YX
 * @version:1.0
 * @date:2014-10-21 下午2:47:08
 */
public class StringUtils {
  private static final String TAG = "StringUtils";
  private static int count = 100000000;

  public static void checkEmpty1(String str) {
    long start = System.currentTimeMillis();
    for (int i = 0; i < count; i++) {
      if (str == null || str.length() < 1) {
      }
    }
    long end = System.currentTimeMillis();
    Log.i(TAG, "checkEmpty1 --- " + (end - start));
  }

  @SuppressLint("NewApi")
  public static void checkEmpty2(String str) {
    long start = System.currentTimeMillis();
    for (int i = 0; i < count; i++) {
      if (str == null || str.isEmpty()) {
      }
    }
    long end = System.currentTimeMillis();
    Log.i(TAG, "checkEmpty2 --- " + (end - start));
  }

  public static void checkEmpty3(String str) {
    long start = System.currentTimeMillis();
    for (int i = 0; i < count; i++) {
      if (str == null || str == "") {
      }
    }
    long end = System.currentTimeMillis();
    Log.i(TAG, "checkEmpty3 --- " + (end - start));
  }

  public static void checkEmpty4(String str) {
    long start = System.currentTimeMillis();
    for (int i = 0; i < count; i++) {
      if (str == null || str.equals("")) {
      }
    }
    long end = System.currentTimeMillis();
    Log.i(TAG, "checkEmpty4 --- " + (end - start));

  }

  public static void checkEmpty5(String str) {
    long start = System.currentTimeMillis();
    for (int i = 0; i < count; i++) {
      if (str == null || TextUtils.isEmpty(str)) {
      }
    }
    long end = System.currentTimeMillis();
    Log.i(TAG, "checkEmpty5 --- " + (end - start));

  }

  public static void checkEmpty11(String str) {
    long start = System.currentTimeMillis();
    for (int i = 0; i < count; i++) {
      if (str != null && str.length() > 0) {
      }
    }
    long end = System.currentTimeMillis();
    Log.i(TAG, "checkEmpty11 --- " + (end - start));
  }

  @SuppressLint("NewApi")
  public static void checkEmpty22(String str) {
    long start = System.currentTimeMillis();
    for (int i = 0; i < count; i++) {
      if (str != null && !str.isEmpty()) {
      }
    }
    long end = System.currentTimeMillis();
    Log.i(TAG, "checkEmpty22 --- " + (end - start));
  }

  public static void checkEmpty33(String str) {
    long start = System.currentTimeMillis();
    for (int i = 0; i < count; i++) {
      if (str != null && str != "") {
      }
    }
    long end = System.currentTimeMillis();
    Log.i(TAG, "checkEmpty33 --- " + (end - start));
  }

  public static void checkEmpty44(String str) {
    long start = System.currentTimeMillis();
    for (int i = 0; i < count; i++) {
      if (str != null && !str.equals("")) {
      }
    }
    long end = System.currentTimeMillis();
    Log.i(TAG, "checkEmpty44 --- " + (end - start));

  }

  public static void checkEmpty55(String str) {
    long start = System.currentTimeMillis();
    for (int i = 0; i < count; i++) {
      if (str != null && !TextUtils.isEmpty(str)) {
      }
    }
    long end = System.currentTimeMillis();
    Log.i(TAG, "checkEmpty55 --- " + (end - start));

  }

}