org.springframework.boot.actuate.system.EmbeddedServerPortFileWriter.java Source code

Introduction

Here is the source code for org.springframework.boot.actuate.system.EmbeddedServerPortFileWriter.java

Source

/*
 * Copyright 2012-2015 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.springframework.boot.actuate.system;

import java.io.File;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.boot.context.embedded.EmbeddedServletContainerInitializedEvent;
import org.springframework.boot.context.embedded.EmbeddedWebApplicationContext;
import org.springframework.context.ApplicationListener;
import org.springframework.util.Assert;
import org.springframework.util.FileCopyUtils;
import org.springframework.util.StringUtils;

/**
 * An {@link ApplicationListener} that saves embedded server port and management port into
 * file. This application listener will be triggered whenever the servlet container
 * starts, and the file name can be overridden at runtime with a System property or
 * environment variable named "PORTFILE" or "portfile".
 *
 * @author David Liu
 * @author Phillip Webb
 * @author Andy Wilkinson
 *
 * @since 1.2.0
 */
public class EmbeddedServerPortFileWriter implements ApplicationListener<EmbeddedServletContainerInitializedEvent> {

    private static final String DEFAULT_FILE_NAME = "application.port";

    private static final String[] PROPERTY_VARIABLES = { "PORTFILE", "portfile" };

    private static final Log logger = LogFactory.getLog(EmbeddedServerPortFileWriter.class);

    private final File file;

    /**
     * Create a new {@link EmbeddedServerPortFileWriter} instance using the filename
     * 'application.port'.
     */
    public EmbeddedServerPortFileWriter() {
        this(new File(DEFAULT_FILE_NAME));
    }

    /**
     * Create a new {@link EmbeddedServerPortFileWriter} instance with a specified
     * filename.
     * @param filename the name of file containing port
     */
    public EmbeddedServerPortFileWriter(String filename) {
        this(new File(filename));
    }

    /**
     * Create a new {@link EmbeddedServerPortFileWriter} instance with a specified file.
     * @param file the file containing port
     */
    public EmbeddedServerPortFileWriter(File file) {
        Assert.notNull(file, "File must not be null");
        String override = SystemProperties.get(PROPERTY_VARIABLES);
        if (override != null) {
            this.file = new File(override);
        } else {
            this.file = file;
        }
    }

    @Override
    public void onApplicationEvent(EmbeddedServletContainerInitializedEvent event) {
        File portFile = getPortFile(event.getApplicationContext());
        try {
            String port = String.valueOf(event.getEmbeddedServletContainer().getPort());
            createParentFolder(portFile);
            FileCopyUtils.copy(port.getBytes(), portFile);
            portFile.deleteOnExit();
        } catch (Exception ex) {
            logger.warn(String.format("Cannot create port file %s", this.file));
        }
    }

    /**
     * Return the actual port file that should be written for the given application
     * context. The default implementation builds a file from the source file and the
     * application context namespace.
     * @param applicationContext the source application context
     * @return the file that should be written
     */
    protected File getPortFile(EmbeddedWebApplicationContext applicationContext) {
        String contextName = applicationContext.getNamespace();
        if (StringUtils.isEmpty(contextName)) {
            return this.file;
        }
        String name = this.file.getName();
        String extension = StringUtils.getFilenameExtension(this.file.getName());
        name = name.substring(0, name.length() - extension.length() - 1);
        if (isUpperCase(name)) {
            name = name + "-" + contextName.toUpperCase();
        } else {
            name = name + "-" + contextName.toLowerCase();
        }
        if (StringUtils.hasLength(extension)) {
            name = name + "." + extension;
        }
        return new File(this.file.getParentFile(), name);
    }

    private boolean isUpperCase(String name) {
        for (int i = 0; i < name.length(); i++) {
            if (Character.isLetter(name.charAt(i)) && !Character.isUpperCase(name.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    private void createParentFolder(File file) {
        File parent = file.getParentFile();
        if (parent != null) {
            parent.mkdirs();
        }
    }

}