java反射

public class Program {
	public String str = "Hello";

	public Program() {
	}

	public Program(String str, Date date, int i) {
		this.str = str;
	}

	public String getStr() {
		return str;
	}

	public void setStr(String str) {
		this.str = str;
	}

	public static void main(String[] args) throws  SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException {
		Program program = new Program();
		Class progClass = program.getClass();
		Field strField = progClass.getField("str");
		strField.set(program, "World");
		System.out.println(program.str);
	}

}