【发布时间】：2016-07-21 10:44:50
【问题描述】：
我正在尝试借助 Talend Jaspersoft ETL Express 5.6 版将数据从 REST API 获取到我们的数据库。 为了确保我的问题与我们的服务器配置无关，我也在本地安装了该工具并卡住了。由于我是一名学生，对 java 的经验并不丰富，但需要为他的公司进行这项工作，我希望你能帮助我。我只有一些基础知识，所以我没有尝试在“代码”选项卡中找到解决方案，只与设计师合作。
最后我想试试下面的教程： http://dwetl.com/2015/08/11/trest-use-case-example-use-rest-api-in-talend/ 但这对我也不起作用。当我在浏览器中使用调用时，我可以获取数据，但使用该工具我只会收到错误。
使用“https://api.github.com/users/mralexgray/followers”作为 URL 我得到一个 UnknownHostException：
Starte Job Test am 11:20 21/07/2016.
[statistics] connecting to socket on port 3941
[statistics] connected
Exception in component tREST_1
com.sun.jersey.api.client.ClientHandlerException: java.net.UnknownHostException: api.github.com
at com.sun.jersey.client.urlconnection.URLConnectionClientHandler.handle(URLConnectionClientHandler.java:131)
at com.sun.jersey.api.client.Client.handle(Client.java:616)
at com.sun.jersey.api.client.WebResource.handle(WebResource.java:559)
at com.sun.jersey.api.client.WebResource.get(WebResource.java:182)
at testetl.test_0_1.Test.tREST_1Process(Test.java:572)
at testetl.test_0_1.Test.runJobInTOS(Test.java:929)
at testetl.test_0_1.Test.main(Test.java:786)
Caused by: java.net.UnknownHostException: api.github.com
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at sun.security.ssl.SSLSocketImpl.connect(Unknown Source)
at sun.security.ssl.BaseSSLSocketImpl.connect(Unknown Source)
at sun.net.NetworkClient.doConnect(Unknown Source)
[statistics] disconnected
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.protocol.https.HttpsClient.<init>(Unknown Source)
at sun.net.www.protocol.https.HttpsClient.New(Unknown Source)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at java.net.HttpURLConnection.getResponseCode(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(Unknown Source)
at com.sun.jersey.client.urlconnection.URLConnectionClientHandler._invoke(URLConnectionClientHandler.java:218)
at com.sun.jersey.client.urlconnection.URLConnectionClientHandler.handle(URLConnectionClientHandler.java:129)
... 6 more
Job Test endet am 11:20 21/07/2016. [exit code=1]
如果我切断“https://”部分并使用“api.github.com/users/mralexgray/followers”作为网址，我会收到错误“Uri is not absolute”
Starte Job Test am 11:31 21/07/2016.
[statistics] connecting to socket on port 3809
[statistics] connected
Exception in component tREST_1
com.sun.jersey.api.client.ClientHandlerException: java.lang.IllegalArgumentException: URI is not absolute
at com.sun.jersey.client.urlconnection.URLConnectionClientHandler.handle(URLConnectionClientHandler.java:131)
at com.sun.jersey.api.client.Client.handle(Client.java:616)
at com.sun.jersey.api.client.WebResource.handle(WebResource.java:559)
at com.sun.jersey.api.client.WebResource.get(WebResource.java:182)
at testetl.test_0_1.Test.tREST_1Process(Test.java:572)
at testetl.test_0_1.Test.runJobInTOS(Test.java:929)
at testetl.test_0_1.Test.main(Test.java:786)
Caused by: java.lang.IllegalArgumentException: URI is not absolute
at java.net.URI.toURL(Unknown Source)
at com.sun.jersey.client.urlconnection.URLConnectionClientHandler._invoke(URLConnectionClientHandler.java:140)
at com.sun.jersey.client.urlconnection.URLConnectionClientHandler.handle(URLConnectionClientHandler.java:129)
... 6 more
[statistics] disconnected
Job Test endet am 11:31 21/07/2016. [exit code=1]
只是为了给你尽可能多的信息，这里是自动生成的 java 代码的一小部分，对我来说似乎是关于这个 REST 调用的，但也许我完全错了，这根本没有帮助，因为我只有基本的java知识：
/**
* [tREST_1 begin ] start
*/
ok_Hash.put("tREST_1", false);
start_Hash.put("tREST_1", System.currentTimeMillis());
currentComponent = "tREST_1";
int tos_count_tREST_1 = 0;
String endpoint_tREST_1 = "api.github.com/users/mralexgray/followers";
String trustStoreFile_tREST_1 = System
.getProperty("javax.net.ssl.trustStore");
String trustStoreType_tREST_1 = System
.getProperty("javax.net.ssl.trustStoreType");
String trustStorePWD_tREST_1 = System
.getProperty("javax.net.ssl.trustStorePassword");
String keyStoreFile_tREST_1 = System
.getProperty("javax.net.ssl.keyStore");
String keyStoreType_tREST_1 = System
.getProperty("javax.net.ssl.keyStoreType");
String keyStorePWD_tREST_1 = System
.getProperty("javax.net.ssl.keyStorePassword");
com.sun.jersey.api.client.config.ClientConfig config_tREST_1 = new com.sun.jersey.api.client.config.DefaultClientConfig();
javax.net.ssl.SSLContext ctx_tREST_1 = javax.net.ssl.SSLContext
.getInstance("SSL");
javax.net.ssl.TrustManager[] tms_tREST_1 = null;
if (trustStoreFile_tREST_1 != null
&& trustStoreType_tREST_1 != null) {
char[] password_tREST_1 = null;
if (trustStorePWD_tREST_1 != null)
password_tREST_1 = trustStorePWD_tREST_1.toCharArray();
java.security.KeyStore trustStore_tREST_1 = java.security.KeyStore
.getInstance(trustStoreType_tREST_1);
trustStore_tREST_1.load(new java.io.FileInputStream(
trustStoreFile_tREST_1), password_tREST_1);
javax.net.ssl.TrustManagerFactory tmf_tREST_1 = javax.net.ssl.TrustManagerFactory
.getInstance(javax.net.ssl.KeyManagerFactory
.getDefaultAlgorithm());
tmf_tREST_1.init(trustStore_tREST_1);
tms_tREST_1 = tmf_tREST_1.getTrustManagers();
}
javax.net.ssl.KeyManager[] kms_tREST_1 = null;
if (keyStoreFile_tREST_1 != null
&& keyStoreType_tREST_1 != null) {
char[] password_tREST_1 = null;
if (keyStorePWD_tREST_1 != null)
password_tREST_1 = keyStorePWD_tREST_1.toCharArray();
java.security.KeyStore keyStore_tREST_1 = java.security.KeyStore
.getInstance(keyStoreType_tREST_1);
keyStore_tREST_1.load(new java.io.FileInputStream(
keyStoreFile_tREST_1), password_tREST_1);
javax.net.ssl.KeyManagerFactory kmf_tREST_1 = javax.net.ssl.KeyManagerFactory
.getInstance(javax.net.ssl.KeyManagerFactory
.getDefaultAlgorithm());
kmf_tREST_1.init(keyStore_tREST_1, password_tREST_1);
kms_tREST_1 = kmf_tREST_1.getKeyManagers();
}
ctx_tREST_1.init(kms_tREST_1, tms_tREST_1, null);
config_tREST_1
.getProperties()
.put(com.sun.jersey.client.urlconnection.HTTPSProperties.PROPERTY_HTTPS_PROPERTIES,
new com.sun.jersey.client.urlconnection.HTTPSProperties(
new javax.net.ssl.HostnameVerifier() {
public boolean verify(
String hostName,
javax.net.ssl.SSLSession session) {
return true;
}
}, ctx_tREST_1));
com.sun.jersey.api.client.Client restClient_tREST_1 = com.sun.jersey.api.client.Client
.create(config_tREST_1);
com.sun.jersey.api.client.WebResource restResource_tREST_1;
if (endpoint_tREST_1 != null && !("").equals(endpoint_tREST_1)) {
restResource_tREST_1 = restClient_tREST_1
.resource(endpoint_tREST_1);
} else {
throw new IllegalArgumentException("url can't be empty!");
}
com.sun.jersey.api.client.ClientResponse errorResponse_tREST_1 = null;
String restResponse_tREST_1 = "";
try {
restResponse_tREST_1 = restResource_tREST_1
.get(String.class);
} catch (com.sun.jersey.api.client.UniformInterfaceException ue) {
errorResponse_tREST_1 = ue.getResponse();
}
// for output
row1 = new row1Struct();
if (errorResponse_tREST_1 != null) {
row1.ERROR_CODE = errorResponse_tREST_1.getStatus();
} else {
row1.Body = restResponse_tREST_1;
}
/**
* [tREST_1 begin ] stop
*/
/**
* [tREST_1 main ] start
*/
任何帮助将不胜感激:)。我所有的例子都是关于那个教程的，但是当我试图让我们真正的 API 与 ETL 一起工作时，我遇到了完全相同的问题，我想这个教程作为例子更容易给你们。
【问题讨论】：