String 与 StringBuffer 可以互相转换。
一个是线程安全的,一个是非线程安全的。
public final class Person {
private final String name;
private final String address;
public Person(String name, String address) {
this.name = name;
this.address = address;
}
public String getName() {
return name;
}
public String getAddress() {
return address;
}
public String toString() {
return "[ Person: name = " + name + ", address = " + address + " ]";
}
}
public class PrintPersonThread extends Thread {
private Person person;
public PrintPersonThread(Person person) {
this.person = person;
}
public void run() {
while (true) {
System.out.println(Thread.currentThread().getName() + " prints " + person);
}
}
}
public class Main {
public static void main(String[] args) {
Person alice = new Person("Alice", "Alaska");
new PrintPersonThread(alice).start();
new PrintPersonThread(alice).start();
new PrintPersonThread(alice).start();
}
}
类中字段不会被修改。所以是安全的。