spring-Resource-01

Posted 2021-01-21

1、读取不同资源

字节码 

public class ByteArrayResourceDemo {

    public static void main(String[] args) throws IOException {
        // 设置了内存的输入资源
        Resource resource = new ByteArrayResource("Hello World".getBytes()) ;

        if (resource.exists()) { //现在资源存在
            //如果要想进行资源的读取，肯定要通过Resource父接口InputStreamResource完成
            Scanner scan = new Scanner(resource.getInputStream()); 
            scan.useDelimiter("
") ;
            while(scan.hasNext()) {
                System.out.println(scan.next());
            }
            scan.close();
        }
    }

}

从文件读取

    public static void main(String[] args) throws IOException {
        File file = new File("D:" + File.separator + "msg.txt") ;
        // 设置了内存的输入资源
        Resource resource = new FileSystemResource(file) ;

        if (resource.exists()) { //现在资源存在
            //如果要想进行资源的读取，肯定要通过Resource父接口InputStreamResource完成
            Scanner scan = new Scanner(resource.getInputStream()); 
            scan.useDelimiter("
") ;
            while(scan.hasNext()) {
                System.out.println(scan.next());
            }
            scan.close();
        }
    }

classpath读取

    public static void main(String[] args) throws IOException {
        // 设置了内存的输入资源
        Resource resource = new ClassPathResource("applicationContext.xml") ;

        if (resource.exists()) { //现在资源存在
            //如果要想进行资源的读取，肯定要通过Resource父接口InputStreamResource完成
            Scanner scan = new Scanner(resource.getInputStream()); 
            scan.useDelimiter("
") ;
            while(scan.hasNext()) {
                System.out.println(scan.next());
            }
            scan.close();
        }
    }

DefaultResourceLoader

http 通过网络读取

file通过文件读取

classpath通过classpath读取

    public static void main(String[] args) throws IOException {
        ResourceLoader loader = new DefaultResourceLoader() ;
        Resource resource = loader.getResource("file:d:\msg.txt");
        if (resource.exists()) { //现在资源存在
            //如果要想进行资源的读取，肯定要通过Resource父接口InputStreamResource完成
            Scanner scan = new Scanner(resource.getInputStream()); 
            scan.useDelimiter("
") ;
            while(scan.hasNext()) {
                System.out.println(scan.next());
            }
            scan.close();
        }
    }

    public static void main(String[] args) throws IOException {
        ResourceLoader loader = new DefaultResourceLoader() ;
        Resource resource = loader.getResource("classpath:applicationContext.xml");
        if (resource.exists()) { //现在资源存在
            //如果要想进行资源的读取，肯定要通过Resource父接口InputStreamResource完成
            Scanner scan = new Scanner(resource.getInputStream()); 
            scan.useDelimiter("
") ;
            while(scan.hasNext()) {
                System.out.println(scan.next());
            }
            scan.close();
        }
    }

Resource自动装配

->MyResource

public class MyResource {
    private Resource resource ;

    public Resource getResource() {
        return resource;
    }

    public void setResource(Resource resource) {
        this.resource = resource;
    }
    
    public void print() throws IOException {
        if (this.resource.exists()) { //现在资源存在
            //如果要想进行资源的读取，肯定要通过Resource父接口InputStreamResource完成
            Scanner scan = new Scanner(this.resource.getInputStream()); 
            scan.useDelimiter("
") ;
            while(scan.hasNext()) {
                System.out.println(scan.next());
            }
            scan.close();
        }
    }
}

->applicationContext.xml

    <bean id="myres" class="cn.mldn.util.MyResource">
        <property name="resource" value="file:d:\msg.txt" />
    </bean>

->test

    public static void main(String[] args) throws Exception {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
        MyResource mr = ctx.getBean("myres",MyResource.class);
        mr.print();
    }