String, StringBuffer, character array conversion

1.Convert StringBuffer to String:

StringBuffer buffer = new StringBuffer(“Hello World.”);
String str = buffer.toString(); 

2.Convert String to StringBuffer:

1、利用构造函数
String str = “Hello World.”;
StringBuffer buffer = new StringBuffer(str);

2、调用append函数
String str = “Hello World.”;       
StringBuffer buffer2 = new StringBuffer();
buffer2.append(str);

3.Convert String to character array:

String str = “Hello World.”;
char[] ch = str.toCharArray();

4. Convert character array to String:

1、利用String类的构造函数，直接在构造String时完成转换。
char[] ch = {'a', 'b', 'c'};
String str = new String(ch);

2、调用String类的valueOf函数转换。
String.valueOf(char[] ch); 

5.Convert StringBuffer to character array:

Java does not support conversion from StringBuffer to character array. You can first convert the StringBuffer to String, and then convert the String to a character array.

StringBuffer buffer = new StringBuffer(“Hello World.”);
String str = buffer.toString();
char[] ch = str.toCharArray();

6. Convert character array to StringBuffer:

char[] ch= {'H', 'e', 'l','l', 'o', 'd'};
String str = new String();
str.valueOf(char[] ch);  // 组转换成String  
StringBuffer buffer1 = new StringBuffer(str); 

StringBuffer buffer2 = new StringBuffer(); 
buffer2.append(str);