Java字符串的等于不等

class StringTest {static boolean f1(){String str1 = new String("blue_仰望");String str2 = new String("blue_仰望");//String str3 = str1;return str1==str2;}static boolean f2(){String str1 = new String("blue_仰望");//String str2 = new String("blue_仰望");String str3 = str1;return str1==str3;}static boolean f3(){String str1 = "blue_仰望";String str2 = "blue";String str3 = str2 + "_仰望";return str1==str3;}static boolean f4(){String str1 = new String("blue_仰望");String str2 = new String("blue_仰望");return 0==str1.compareTo(str2);}static boolean f5(){String str1 = new String("blue_仰望");String str2 = new String("blue_仰望");return str1.equals(str2);}public static void main(String[] args){if(f1()) //falseSystem.out.println("f1()为真");elseSystem.out.println("f1()为假");if(f2()) //trueSystem.out.println("f2()为真");elseSystem.out.println("f2()为假");if(f3()) //falseSystem.out.println("f3()为真");elseSystem.out.println("f3()为假");if(f4()) //trueSystem.out.println("f4()为真");elseSystem.out.println("f4()为假");if(f5()) //trueSystem.out.println("f5()为真");elseSystem.out.println("f5()为假");}}