没有XML的Spring Bean注释

这将不需要任何xml配置

public class App { public static void main(String[] args) {  ApplicationContext ctx = new AnnotationConfigApplicationContext(Config.class);  Logger logger = ctx.getBean(Logger.class);  logger.writeConsole("Hello there");  logger.writeFile("Hi again"); }}

配置类

@Configuration@ComponentScanpublic class Config {}

控制台作家

@Componentpublic class ConsoleWriter implements LogWriter{  public void write(String text) {      System.out.println("Console Writer: "+text);  }}

FileWriter

@Componentpublic class FileWriter implements LogWriter {   public void write(String text) {      System.out.println("FileWriter: " + text);   }}

懒汉

@Componentpublic class Logger {@Autowiredprivate ConsoleWriter consoleWriter;@Autowiredprivate FileWriter fileWriter;public void setConsoleWriter(ConsoleWriter consoleWriter) {    this.consoleWriter = consoleWriter;}public void setFileWriter(FileWriter fileWriter) {    this.fileWriter = fileWriter;}public void writeFile(String text) {    fileWriter.write(text);}public void writeConsole(String text) {    consoleWriter.write(text);}

}

接口LogWriter

public interface LogWriter {  public void write(String text);}