如何比较Java中的字符串？

String str1 = "Hello";
String str2 = "World";
String str3 = "Hello";

boolean result1 = str1.equals(str2); // false
boolean result2 = str1.equals(str3); // true

String str1 = "Hello";
String str2 = "World";
String str3 = "Hello";

int result1 = str1.compareTo(str2); // negative value
int result2 = str1.compareTo(str3); // 0
int result3 = str2.compareTo(str1); // positive value

String str1 = "Hello";
String str2 = "hello";

boolean result = str1.equalsIgnoreCase(str2); // true

String str1 = "Hello";
String str2 = "World";
String str3 = "Hello";
char[] charArray1 = {'H', 'e', 'l', 'l', 'o'};
char[] charArray2 = {'W', 'o', 'r', 'l', 'd'};

boolean result1 = str1.contentEquals(charArray1); // true
boolean result2 = str1.contentEquals(charArray2); // false