hessian轻量级的二进制webservices

hessian是一个轻量级的二进制webservices

1.自定义对像必须要实现Serializable接口, 这样才可被序列/反序列，要不能会抛异常

public class Book implements Serializable{
	private int id;
	private String name;
	private double price;
      // getters and setters......
}

2.一个接口

public interface Service {
	public String sayHello();
	public List getAllBooks();
	public Book getBook();
}

3.实现自定义的接口

public class ServiceImpl implements Service {

	public String sayHello() {
		return "this is a simple test";
	}

	public List<Book> getAllBooks() {
		List<Book> bookList = new ArrayList<Book>();
		for (int i = 0; i < 30; i++) {
			Book book = new Book();
			book.setId(i);
			book.setName("name_" + i);
			book.setPrice(20 * i);
			bookList.add(book);
		}
		return bookList;
	}

	public Book getBook() {
		Book book = new Book();
		book.setId(1);
		book.setName("book_name");
		book.setPrice(123.0);
		return book;
	}
}

4. 在web.xml文件中配置hessian

<servlet>
		<servlet-name>Hello</servlet-name>
		<servlet-class>
			com.caucho.hessian.server.HessianServlet
		</servlet-class>

		<init-param>
			<param-name>service-class</param-name>
			<param-value>com.test.hessian.ServiceImpl</param-value>
		</init-param>

	</servlet>
	
	<servlet-mapping>
		<servlet-name>Hello</servlet-name>
		<url-pattern>/hello</url-pattern>
	</servlet-mapping>
	

5.如果实现类实现类自定义的接口 并从HessianServlet继承。

public class WSServlet extends HessianServlet implements Service {
	public String sayHello() {
		return "this is a simple test";
	}

	public List<Book> getAllBooks() {
		List<Book> bookList = new ArrayList<Book>();
		for (int i = 0; i < 30; i++) {
			Book book = new Book();
			book.setId(i);
			book.setName("name_" + i);
			book.setPrice(20 * i);
			bookList.add(book);
		}
		return bookList;
	}

	public Book getBook() {
		Book book = new Book();
		book.setId(1);
		book.setName("book_name");
		book.setPrice(123.0);
		return book;
	}

}

那么在web.xml文件中既可以这样配置

<servlet>
		<servlet-name>Hello</servlet-name>
		<servlet-class>
			com.test.hessian.WSServlet
		</servlet-class>
	</servlet>
	
	<servlet-mapping>
		<servlet-name>Hello</servlet-name>
		<url-pattern>/hello</url-pattern>
	</servlet-mapping>

6.编写客户端

public class Client {

	@SuppressWarnings("unchecked")
	public static void main(String args[]){
		
		//发布的服务的url
		String url="http://localhost:8080/hessian/hello";
		//生成工厂
		HessianProxyFactory factory = new HessianProxyFactory();
		try {
			//生成服务对像
			Service service = (Service)factory.create(Service.class, url);
			System.out.println(service.sayHello());
			
			//调用java对像
			Book book = service.getBook();
			System.out.println(book.getName());
			long startTime = System.currentTimeMillis();
			List<Book> books = service.getAllBooks();
			int length = books.size();
			for(int i=0; i<length; i++){
				Book b = books.get(i);
				System.out.println("id="+b.getId()+",name="+b.getName()+",price="+b.getPrice());
				
			}
			
			long endTime = System.currentTimeMillis();
			
			System.out.println(endTime - startTime);
		} catch (MalformedURLException e) {
			e.printStackTrace();
		}
	}
	
}

7.hessian在处理大量数据的时候性能很低