REST:Atom的开源框架Apache Abdera

     Apache Abdera的目标是高效的实现Atom Syndication Format(简称Atom)  和 Atom Publishing Protocol(简称AtomPub) 定义的规范,并且功能完整，性能高。

AtomPub Server

Abdera提供classes对应atomPub的basics,详细概念解释见上篇。

• Services - Provider
• Workspaces - WorkspaceInfo & WorkspaceManager
• Collections - CollectionAdapter
  

引入maven最小依赖

<dependency>  <groupId>org.apache.abdera</groupId>  <artifactId>abdera-server</artifactId>  <version>1.1.1</version></dependency>

CollectionAdapter

public class Employee {     private int id;     private String name;     private Date updated;     public int getId() {         return id;     }     public void setId(int id) {         this.id = id;     }     public String getName() {         return name;     }     public void setName(String name) {         this.name = name;     }     public Date getUpdated() {         return updated;     }     public void setUpdated(Date updated) {         this.updated = updated;     } }

AtomPub Client
添加maven最小依赖

<dependency>  <groupId>org.apache.abdera</groupId>  <artifactId>abdera-client</artifactId>  <version>1.1.1</version> </dependency>

检索资源（GET）

Abdera abdera = new Abdera();AbderaClient client = new AbderaClient(abdera);ClientResponse resp = client.get("http://localhost:8080/abdera-server-example/employee");if (resp.getType() == ResponseType.SUCCESS) {  Document<Feed> doc = resp.getDocument();} else {  // there was an error}

如果资源不是XML 文档，ClientResponse提供了inputStream

InputStream in = resp.getInputStream();resp.getContentType();

ClientResponse提供范围headers的方法，比如ETag ,Last-Modified

System.out.println(resp.getEntityTag());System.out.println(resp.getLastModified());System.out.println(resp.getContentLocation());System.out.println(resp.getSlug())

客户端解析Atom Document并且打印entry titles

Abdera abdera = new Abdera();Parser parser = abdera.getParser();             URL url = new URL("http://intertwingly.net/blog/index.atom");Document<Feed> doc = parser.parse(url.openStream(),url.toString());Feed feed = doc.getRoot();System.out.println(feed.getTitle());for (Entry entry : feed.getEntries()) {  System.out.println("\t" + entry.getTitle());}System.out.println (feed.getAuthor());

创建资源(POST)

AbderaClient client = new AbderaClient(abdera); Entry entry = abdera.newEntry();       entry.setId(...);entry.setTitle(...);entry.setUpdated(...);entry.setContent(...);//... ClientResponse resp = client.post("http://localhost:8080/abdera-server-example/employee",entry); if (resp.getType() == ResponseType.SUCCESS) {  // success} else {  // there was an error}

更新资源(PUT)

AbderaClient client = new AbderaClient(abdera); Entry entry = abdera.newEntry();// ... ClientResponse resp = client.put("http://www.example.org/collection",entry); if (resp.getType() == ResponseType.SUCCESS) {  // success} else {  // there was an error}

删除资源

AbderaClient client = new AbderaClient(abdera); ClientResponse resp = client.delete("http://www.example.org/collection"); if (resp.getType() == ResponseType.SUCCESS) {  // success} else {  // there was an error}

使用传统的HTTP方法

Abdera abdera = Abdera.getInstance();AbderaClient client = new AbderaClient(abdera); RequestEntity entity = ...client.execute("PATCH", "http://example.org/foo", entity, null); if (resp.getType() == ResponseType.SUCCESS) {  // success} else {  // there was an error}

请求选项

RequestOptions options = client.getDefaultRequestOptions();options.setIfMatch(new EntityTag("foo"));options.setNoCache(true); ClientResponse resp = client.get("http://example.org/foo", options); if (resp.getType() == ResponseType.SUCCESS) {  // success} else {  // there was an error}

使用SSL

Abdera abdera = new Abdera();AbderaClient client = new AbderaClient(abdera);     // Default trust manager provider registered for port 443AbderaClient.registerTrustManager();     client.get("https://localhost:9080/foo");

未完待续。。。

参考：

https://cwiki.apache.org/confluence/display/ABDERA/AtomPub+Client

http://abdera.apache.org/index.html