(no commit message)

[utils] / crawler / basic / src / org / wamblee / crawler / impl / ConfigurationParser.java

diff --git a/crawler/basic/src/org/wamblee/crawler/impl/ConfigurationParser.java b/crawler/basic/src/org/wamblee/crawler/impl/ConfigurationParser.java
new file mode 100644 (file)
index 0000000..89e815c
--- /dev/null
+++ b/crawler/basic/src/org/wamblee/crawler/impl/ConfigurationParser.java
@@ -0,0 +1,141 @@
+/*
+ * Copyright 2005 the original author or authors.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.wamblee.crawler.impl;
+
+import java.io.InputStream;
+import java.io.PrintStream;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import org.apache.commons.httpclient.NameValuePair;
+import org.dom4j.Document;
+import org.dom4j.DocumentException;
+import org.dom4j.Element;
+import org.dom4j.io.SAXReader;
+import org.wamblee.crawler.Configuration;
+import org.wamblee.crawler.GetPageRequest;
+import org.wamblee.crawler.PageRequest;
+import org.wamblee.crawler.PostPageRequest;
+
+/**
+ * Parsing of the configuration from an XML file.
+ */
+public class ConfigurationParser {
+    
+    private static final String ELEM_URL = "url"; 
+    private static final String ELEM_TYPE = "type";
+    private static final String ELEM_PATTERN = "pattern"; 
+    private static final String ELEM_METHOD= "method"; 
+    private static final String ELEM_XSLT = "xslt"; 
+    private static final String ELEM_PARAM = "param"; 
+    private static final String AT_NAME = "name";
+    private static final String AT_VALUE = "value";
+    
+    private static final String METHOD_POST = "post";
+    private static final String METHOD_GET = "get";
+    
+    private PrintStream _os; 
+    
+    public ConfigurationParser(PrintStream aOs) {
+        _os = aOs;
+    }
+
+    public Configuration parse(InputStream aStream) {
+        try {
+            SAXReader reader = new SAXReader();
+            Document document = reader.read(aStream);
+            
+            Element root = document.getRootElement(); 
+            List<UrlConfig> urlConfigs = parseUrlConfigs(root);
+            List<PageTypeConfig> pageTypeConfigs = parsePageTypeConfigs(root); 
+            return new ConfigurationImpl(urlConfigs, pageTypeConfigs);
+        } catch (DocumentException e) {
+            throw new RuntimeException("Problem parsing config file", e);
+        }
+    }
+
+    /**
+     * @param root
+     * @return
+     */
+    private List<UrlConfig> parseUrlConfigs(Element root) {
+        List<UrlConfig> configs = new ArrayList<UrlConfig>();
+        for (Iterator i = root.elementIterator(ELEM_URL); i.hasNext(); ) { 
+            Element url = (Element)i.next();
+            UrlConfig config = parseUrlConfig(url);
+            configs.add(config);
+        }
+        return configs;
+    }
+    
+    private List<PageTypeConfig> parsePageTypeConfigs(Element root) {
+        List<PageTypeConfig> configs = new ArrayList<PageTypeConfig>();
+        for (Iterator i = root.elementIterator(ELEM_TYPE); i.hasNext(); ) { 
+            Element url = (Element)i.next();
+            PageTypeConfig config = parsePageTypeConfig(url);
+            configs.add(config);
+        }
+        return configs;
+    }
+    
+    private UrlConfig parseUrlConfig(Element aUrlElem) { 
+        String pattern = aUrlElem.elementText(ELEM_PATTERN);
+        PageRequest request = parseRequestConfig(aUrlElem);
+        return new UrlConfig(pattern, request);
+    }
+    
+    private PageTypeConfig parsePageTypeConfig(Element aTypeElem) { 
+        String pattern = aTypeElem.elementText(ELEM_PATTERN);
+        PageRequest request = parseRequestConfig(aTypeElem);
+        return new PageTypeConfig(pattern, request);
+    }
+
+    /**
+     * @param aUrlElem
+     * @return
+     */
+    private PageRequest parseRequestConfig(Element aUrlElem) {
+        String method = aUrlElem.elementText(ELEM_METHOD); 
+        String xslt = aUrlElem.elementText(ELEM_XSLT);
+        List<NameValuePair> params = new ArrayList<NameValuePair>();
+        for (Iterator i = aUrlElem.elementIterator(ELEM_PARAM); i.hasNext(); ) { 
+            Element paramElem = (Element)i.next();
+            NameValuePair param = parseParameter(paramElem);
+            params.add(param);
+        }
+    
+        NameValuePair[] paramsArray = params.toArray(new NameValuePair[0]);
+        PageRequest request; 
+        if ( METHOD_POST.equals(method)) { 
+            request = new PostPageRequest(paramsArray, xslt, _os);
+        }
+        else if ( METHOD_GET.equals(method) || method == null ){
+            request = new GetPageRequest(paramsArray, xslt, _os);
+        } else { 
+            throw new RuntimeException("Unknown request method '" + method + "'. Only " + 
+                    METHOD_GET + " and " + METHOD_POST + " are supported");
+        }
+        return request;
+    }
+    
+    private NameValuePair parseParameter(Element aParam) { 
+        String name = aParam.attributeValue(AT_NAME);
+        String value = aParam.attributeValue(AT_VALUE);
+        return new NameValuePair(name, value);
+    }
+}