/*
* Copyright (c) 2002-2012 Alibaba Group Holding Limited.
* All rights reserved.
*
* 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 com.alibaba.antx.config.entry;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import com.alibaba.antx.config.ConfigResource;
import com.alibaba.antx.config.ConfigSettings;
import com.alibaba.antx.config.descriptor.ConfigDescriptor;
import com.alibaba.antx.config.generator.ConfigGenerator;
import com.alibaba.antx.util.PatternSet;
import com.alibaba.antx.util.SelectorUtil;
import com.alibaba.antx.util.scanner.DefaultScannerHandler;
/**
* 代表一个可配置项的信息。
*
* @author Michael Zhou
*/
public abstract class ConfigEntry {
private ConfigSettings settings;
private ConfigResource resource;
private File outputFile;
private PatternSet descriptorPatterns;
private PatternSet packagePatterns;
protected ConfigEntry[] subEntries;
private final ConfigGenerator generator;
/**
* 创建一个结点。
*
* @param resource 指定结点的资源
* @param settings antxconfig的设置
*/
public ConfigEntry(ConfigResource resource, File outputFile, ConfigSettings settings) {
this.resource = resource;
this.outputFile = outputFile;
this.settings = settings;
this.generator = new ConfigGenerator(settings);
}
/**
* 取得结点的名称。
*
* @return 结点的名称
*/
public String getName() {
return getConfigEntryResource().getName();
}
/** 不包含任何descriptor和sub entries的空结点。 */
public boolean isEmpty() {
return getSubEntries().length == 0 && getGenerator().getConfigDescriptors().length == 0;
}
/**
* 取得资源。
*
* @return 资源
*/
public ConfigResource getConfigEntryResource() {
return resource;
}
/** 取得输出文件或目录。 */
public File getOutputFile() {
return outputFile;
}
/**
* 取得config设置。
*
* @return config设置
*/
public ConfigSettings getConfigSettings() {
return settings;
}
/**
* 取得config descriptor的patterns，如果未设置，则使用默认值。
*
* @return config descriptor的pattern
*/
public PatternSet getDescriptorPatterns() {
return descriptorPatterns;
}
/**
* 设置config descriptor的pattern，如果未设置，则使用默认值。
*
* @param descriptorsPatterns config descriptor的pattern
*/
public void setDescriptorPatterns(PatternSet descriptorPatterns) {
this.descriptorPatterns = descriptorPatterns;
}
/**
* 取得用于匹配当前结点下的所有子结点的pattern。
*
* @return pattern
*/
public PatternSet getPackagePatterns() {
return packagePatterns;
}
/**
* 设置用于匹配当前结点下的所有子结点的pattern。
*
* @param packagePatterns pattern
*/
public void setPackagePatterns(PatternSet packagePatterns) {
this.packagePatterns = packagePatterns;
}
/**
* 取得当前config结点对应的generator。
*
* @return generator对象
*/
public ConfigGenerator getGenerator() {
return generator;
}
/**
* 取得当前config结点下的所有子结点。
*
* @return 子结点数组，如果不存在，则返回空数组
*/
public ConfigEntry[] getSubEntries() {
return subEntries;
}
/** 扫描结点。 */
public void scan() {
scan(null);
}
/** 扫描结点。 */
protected abstract void scan(InputStream istream);
/** 装配descriptor的context，用来生成文件。 */
protected void populateDescriptorContext(Map context, String string) {
}
/** 生成配置文件。 */
public boolean generate() {
if (getOutputFile() != null) {
settings.getOut().printf("Output file: %s%n%n", getOutputFile().getAbsolutePath());
}
return generate(null, null);
}
/** 生成配置文件。 */
protected abstract boolean generate(InputStream istream, OutputStream ostream);
/** 扫描处理器。 */
public class Handler extends DefaultScannerHandler {
private List subEntries = new ArrayList();
public ConfigEntry[] getSubEntries() {
return (ConfigEntry[]) subEntries.toArray(new ConfigEntry[subEntries.size()]);
}
@Override
public void startScanning() {
StringBuffer buffer = new StringBuffer();
buffer.append("Scanning ").append(getScanner().getBaseURL()).append("\n");
buffer.append(" descriptors: ").append(getDescriptorPatterns()).append("\n");
buffer.append(" packages: ").append(getPackagePatterns()).append("\n");
settings.debug(buffer.toString());
}
@Override
public void file() {
String name = getScanner().getPath();
if (isDescriptorFile(name)) {
settings.debug("Loading descriptor " + getScanner().getURL() + "\n");
loadDescriptor();
} else if (isPackageFile(name)) {
ConfigResource resource = new ConfigResource(getScanner().getURL(), name);
ConfigEntryFactory factory = getConfigSettings().getConfigEntryFactory();
ConfigEntry subEntry = createSubEntry(name, resource, factory);
InputStream istream = null;
try {
istream = getScanner().getInputStream();
subEntry.scan(istream);
} finally {
if (istream != null) {
try {
istream.close();
} catch (IOException e) {
}
}
}
if (!subEntry.isEmpty()) {
subEntries.add(subEntry);
}
}
}
@Override
public void directory() {
String name = getScanner().getPath();
if (isPackageFile(name)) {
ConfigResource resource = new ConfigResource(getScanner().getURL(), name);
ConfigEntryFactory factory = getConfigSettings().getConfigEntryFactory();
ConfigEntry subEntry = createSubEntry(name, resource, factory);
subEntry.scan();
if (!subEntry.isEmpty()) {
subEntries.add(subEntry);
}
}
}
private ConfigEntry createSubEntry(String name, ConfigResource resource, ConfigEntryFactory factory) {
ConfigEntry subEntry;
if (outputFile != null && (!outputFile.exists() || outputFile.isDirectory())) {
subEntry = factory.create(resource, new File(outputFile, name), null);
} else {
subEntry = factory.create(resource, null, null);
}
return subEntry;
}
/**
* 是否跟进指定目录或文件。该方法有助于提高扫描速度。
*
* @return 如果是，则返回<code>true</code>
*/
@Override
public boolean followUp() {
String name = getScanner().getPath();
boolean followUp = false;
followUp |= SelectorUtil.matchPathPrefix(name, getDescriptorPatterns().getIncludes(),
getDescriptorPatterns().getExcludes());
followUp |= SelectorUtil.matchPathPrefix(name, getPackagePatterns().getIncludes(), getPackagePatterns()
.getExcludes());
if (isPackageFile(name)) {
return false;
}
if (!followUp) {
getConfigSettings().debug("Skipping directory " + name);
}
return followUp;
}
/** 装入descriptor。 */
private void loadDescriptor() {
URL descriptorURL = getScanner().getURL();
ConfigResource descriptorResource = new ConfigResource(descriptorURL, getScanner().getPath());
ConfigDescriptor descriptor;
InputStream istream = null;
try {
istream = getScanner().getInputStream();
descriptor = getGenerator().addConfigDescriptor(descriptorResource, istream);
} finally {
if (istream != null) {
try {
istream.close();
} catch (IOException e) {
}
}
}
populateDescriptorContext(descriptor.getContext(), descriptor.getName());
}
/**
* 查看指定名称是否符合descriptor的patterns。
*
* @param name 要匹配的名称
* @return 如果符合descriptor的patterns，则返回<code>true</code>
*/
private boolean isDescriptorFile(String name) {
return SelectorUtil.matchPath(name, getDescriptorPatterns().getIncludes(), getDescriptorPatterns()
.getExcludes());
}
/**
* 查看指定名称是否符合jarfile的patterns。
*
* @param name 要匹配的名称
* @return 如果符合jarfile的patterns，则返回<code>true</code>
*/
private boolean isPackageFile(String name) {
return SelectorUtil.matchPath(name, getPackagePatterns().getIncludes(), getPackagePatterns().getExcludes());
}
}
}