Java tutorial
/** * The MIT License * Copyright 2010 JmxTrans team * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package com.googlecode.jmxtrans.model.output; import com.fasterxml.jackson.annotation.JsonProperty; import com.google.common.collect.ImmutableList; import com.googlecode.jmxtrans.model.Query; import com.googlecode.jmxtrans.model.Result; import com.googlecode.jmxtrans.model.Server; import com.googlecode.jmxtrans.model.ValidationException; import com.googlecode.jmxtrans.model.naming.KeyUtils; import lombok.ToString; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.PrintWriter; import java.nio.file.Path; import java.util.List; import java.util.Map; @ToString public class FileWriter extends BaseOutputWriter { private static final String PROPERTY_BASEPATH = "filepath"; private static final String PROPERTY_LINE_FORMAT = "lineFormat"; private static final String DEFAULT_LINE_FORMAT = "%s=%s"; private static final Logger log = LoggerFactory.getLogger(FileWriter.class); private File outputFile; private File outputTempFile; private String lineFormat; public FileWriter(@JsonProperty("typeNames") ImmutableList<String> typeNames, @JsonProperty("booleanAsNumber") boolean booleanAsNumber, @JsonProperty("debug") Boolean debugEnabled, @JsonProperty(PROPERTY_BASEPATH) String filepath, @JsonProperty(PROPERTY_LINE_FORMAT) String lineFormat, @JsonProperty("settings") Map<String, Object> settings) throws IOException { super(typeNames, booleanAsNumber, debugEnabled, settings); this.outputFile = new File(filepath); Path outputFilePath = outputFile.toPath(); this.outputTempFile = new File( outputFilePath.getParent() + File.separator + "." + outputFilePath.getFileName()); if (lineFormat == null) { this.lineFormat = DEFAULT_LINE_FORMAT; } else { this.lineFormat = lineFormat; } // make sure the permissions allow to manage these files: touch(this.outputFile); touch(this.outputTempFile); } private static void touch(File file) throws IOException { new FileOutputStream(file, true).close(); // ensure file exists and it's accessible assert (file.setLastModified(System.currentTimeMillis())); } @Override public void validateSetup(Server server, Query query) throws ValidationException { } @Override protected void internalWrite(Server server, Query query, ImmutableList<Result> results) throws Exception { try (PrintWriter outputTempPrintWriter = new PrintWriter(this.outputTempFile, "UTF-8")) { List<String> typeNames = this.getTypeNames(); for (Result result : results) { log.debug(result.toString()); for (Map.Entry<String, Object> values : result.getValues().entrySet()) { outputTempPrintWriter.printf(lineFormat + System.lineSeparator(), KeyUtils.getKeyString(query, result, values, typeNames), values.getValue()); } } } assert (this.outputTempFile.renameTo(this.outputFile)); } }