如何从java调用GraphViz
如何从java调用GraphViz以及如何使用java调用GraphViz函数？ 为了构建点图，访问GraphViz库需要包含哪些必要的jar文件？ 是否有用于生成点图的示例程序
检查这个 API，它很简单，有几种输出格式（即pdf gif ..etc）。
编辑2016年5月：许多人评论说API不再可用; 这是它的源代码：
首先是config.properties文件，您需要创建并复制粘贴以下内容：
############################################################## # Linux Configurations # ############################################################## # The dir. where temporary files will be created. tempDirForLinux = /tmp # Where is your dot program located? It will be called externally. dotForLinux = /usr/bin/dot ############################################################## # Windows Configurations # ############################################################## # The dir. where temporary files will be created. tempDirForWindows = c:/temp # Where is your dot program located? It will be called externally. dotForWindows = "c:/Program Files (x86)/Graphviz 2.28/bin/dot.exe" ############################################################## # Mac Configurations # ############################################################## # The dir. where temporary files will be created. tempDirForMacOSX = /tmp # Where is your dot program located? It will be called externally. dotForMacOSX = /usr/local/bin/dot
然后是Graphviz.java源代码
// GraphViz.java - a simple API to call dot from Java programs /*$Id$*/ /* ****************************************************************************** * * * (c) Copyright Laszlo Szathmary * * * * This program is free software; you can redistribute it and/or modify it * * under the terms of the GNU Lesser General Public License as published by * * the Free Software Foundation; either version 2.1 of the License, or * * (at your option) any later version. * * * * This program is distributed in the hope that it will be useful, but * * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public * * License for more details. * * * * You should have received a copy of the GNU Lesser General Public License * * along with this program; if not, write to the Free Software Foundation, * * Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * * ****************************************************************************** */ import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.DataInputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.FileWriter; import java.io.InputStreamReader; import java.util.Properties; /** **
- Purpose: GraphViz Java API *
- * *
- Description: *
- With this Java class you can simply call dot * from your Java programs. *
- Example usage: *
- *
* GraphViz gv = new GraphViz(); * gv.addln(gv.start_graph()); * gv.addln("A -> B;"); * gv.addln("A -> C;"); * gv.addln(gv.end_graph()); * System.out.println(gv.getDotSource()); * * String type = "gif"; * File out = new File("out." + type); // out.gif in this example * gv.writeGraphToFile( gv.getGraph( gv.getDotSource(), type ), out ); **
* *
* * @version v0.5.1, 2013/03/18 (March) -- Patch of Juan Hoyos (Mac support) * @version v0.5, 2012/04/24 (April) -- Patch of Abdur Rahman (OS detection + start subgraph + * read config file) * @version v0.4, 2011/02/05 (February) -- Patch of Keheliya Gallaba is added. Now you * can specify the type of the output file: gif, dot, fig, pdf, ps, svg, png, etc. * @version v0.3, 2010/11/29 (November) -- Windows support + ability to read the graph from a text file * @version v0.2, 2010/07/22 (July) -- bug fix * @version v0.1, 2003/12/04 (December) -- first release * @author Laszlo Szathmary (https://stackoverflow.com/questions/26481910/how-to-call-graphviz-from-java/jabba.laci@gmail.com) */ public class GraphViz { /** * Detects the client's operating system. */ private final static String osName = System.getProperty("os.name").replaceAll("\\s",""); /** * Load the config.properties file. */ private final static String cfgProp = "/Users/seteropere/NetBeansProjects/TestApplication/src/config.properties"; private final static Properties configFile = new Properties() { private final static long serialVersionUID = 1L; { try { load(new FileInputStream(cfgProp)); } catch (Exception e) {} } }; /** * The dir. where temporary files will be created. */ private static String TEMP_DIR = "/Users/seteropere/NetBeansProjects/TestApplication"; /** * Where is your dot program located? It will be called externally. */ private static String DOT = configFile.getProperty("dotFor" + osName); /** * The image size in dpi. 96 dpi is normal size. Higher values are 10% higher each. * Lower values 10% lower each. * * dpi patch by Peter Mueller */ private int[] dpiSizes = {46, 51, 57, 63, 70, 78, 86, 96, 106, 116, 128, 141, 155, 170, 187, 206, 226, 249}; /** * Define the index in the image size array. */ private int currentDpiPos = 7; /** * Increase the image size (dpi). */ public void increaseDpi() { if ( this.currentDpiPos < (this.dpiSizes.length - 1) ) { ++this.currentDpiPos; } } /** * Decrease the image size (dpi). */ public void decreaseDpi() { if (this.currentDpiPos > 0) { --this.currentDpiPos; } } public int getImageDpi() { return this.dpiSizes[this.currentDpiPos]; } /** * The source of the graph written in dot language. */ private StringBuilder graph = new StringBuilder(); /** * Constructor: creates a new GraphViz object that will contain * a graph. */ public GraphViz() { } /** * Returns the graph's source description in dot language. * @return Source of the graph in dot language. */ public String getDotSource() { return this.graph.toString(); } /** * Adds a string to the graph's source (without newline). */ public void add(String line) { this.graph.append(line); } /** * Adds a string to the graph's source (with newline). */ public void addln(String line) { this.graph.append(line + "\n"); } /** * Adds a newline to the graph's source. */ public void addln() { this.graph.append('\n'); } public void clearGraph(){ this.graph = new StringBuilder(); } /** * Returns the graph as an image in binary format. * @param dot_source Source of the graph to be drawn. * @param type Type of the output image to be produced, eg: gif, dot, fig, pdf, ps, svg, png. * @return A byte array containing the image of the graph. */ public byte[] getGraph(String dot_source, String type) { File dot; byte[] img_stream = null; try { dot = writeDotSourceToFile(dot_source); if (dot != null) { img_stream = get_img_stream(dot, type); if (dot.delete() == false) System.err.println("Warning: " + dot.getAbsolutePath() + " could not be deleted!"); return img_stream; } return null; } catch (java.io.IOException ioe) { return null; } } /** * Writes the graph's image in a file. * @param img A byte array containing the image of the graph. * @param file Name of the file to where we want to write. * @return Success: 1, Failure: -1 */ public int writeGraphToFile(byte[] img, String file) { File to = new File(file); return writeGraphToFile(img, to); } /** * Writes the graph's image in a file. * @param img A byte array containing the image of the graph. * @param to A File object to where we want to write. * @return Success: 1, Failure: -1 */ public int writeGraphToFile(byte[] img, File to) { try { FileOutputStream fos = new FileOutputStream(to); fos.write(img); fos.close(); } catch (java.io.IOException ioe) { return -1; } return 1; } /** * It will call the external dot program, and return the image in * binary format. * @param dot Source of the graph (in dot language). * @param type Type of the output image to be produced, eg: gif, dot, fig, pdf, ps, svg, png. * @return The image of the graph in .gif format. */ private byte[] get_img_stream(File dot, String type) { File img; byte[] img_stream = null; try { img = File.createTempFile("graph_", "."+type, new File(GraphViz.TEMP_DIR)); Runtime rt = Runtime.getRuntime(); // patch by Mike Chenault String[] args = {DOT, "-T"+type, "-Gdpi="+dpiSizes[this.currentDpiPos], dot.getAbsolutePath(), "-o", img.getAbsolutePath()}; Process p = rt.exec(args); p.waitFor(); FileInputStream in = new FileInputStream(img.getAbsolutePath()); img_stream = new byte[in.available()]; in.read(img_stream); // Close it if we need to if( in != null ) in.close(); if (img.delete() == false) System.err.println("Warning: " + img.getAbsolutePath() + " could not be deleted!"); } catch (java.io.IOException ioe) { System.err.println("Error: in I/O processing of tempfile in dir " + GraphViz.TEMP_DIR+"\n"); System.err.println(" or in calling external command"); ioe.printStackTrace(); } catch (java.lang.InterruptedException ie) { System.err.println("Error: the execution of the external program was interrupted"); ie.printStackTrace(); } return img_stream; } /** * Writes the source of the graph in a file, and returns the written file * as a File object. * @param str Source of the graph (in dot language). * @return The file (as a File object) that contains the source of the graph. */ private File writeDotSourceToFile(String str) throws java.io.IOException { File temp; try { temp = File.createTempFile("dorrr",".dot", new File(GraphViz.TEMP_DIR)); FileWriter fout = new FileWriter(temp); fout.write(str); BufferedWriter br=new BufferedWriter(new FileWriter("dotsource.dot")); br.write(str); br.flush(); br.close(); fout.close(); } catch (Exception e) { System.err.println("Error: I/O error while writing the dot source to temp file!"); return null; } return temp; } /** * Returns a string that is used to start a graph. * @return A string to open a graph. */ public String start_graph() { return "digraph G {"; } /** * Returns a string that is used to end a graph. * @return A string to close a graph. */ public String end_graph() { return "}"; } /** * Takes the cluster or subgraph id as input parameter and returns a string * that is used to start a subgraph. * @return A string to open a subgraph. */ public String start_subgraph(int clusterid) { return "subgraph cluster_" + clusterid + " {"; } /** * Returns a string that is used to end a graph. * @return A string to close a graph. */ public String end_subgraph() { return "}"; } /** * Read a DOT graph from a text file. * * @param input Input text file containing the DOT graph * source. */ public void readSource(String input) { StringBuilder sb = new StringBuilder(); try { FileInputStream fis = new FileInputStream(input); DataInputStream dis = new DataInputStream(fis); BufferedReader br = new BufferedReader(new InputStreamReader(dis)); String line; while ((line = br.readLine()) != null) { sb.append(line); } dis.close(); } catch (Exception e) { System.err.println("Error: " + e.getMessage()); } this.graph = sb; } } // end of class GraphViz
一个例子是：
public static void createDotGraph(String dotFormat,String fileName) { GraphViz gv=new GraphViz(); gv.addln(gv.start_graph()); gv.add(dotFormat); gv.addln(gv.end_graph()); // String type = "gif"; String type = "pdf"; // gv.increaseDpi(); gv.decreaseDpi(); gv.decreaseDpi(); File out = new File(fileName+"."+ type); gv.writeGraphToFile( gv.getGraph( gv.getDotSource(), type ), out ); }像这样调用它：
public static void main(String[] args) throws Exception { String dotFormat="1->2;1->3;1->4;4->5;4->6;6->7;5->7;3->8;3->6;8->7;2->8;2->5;"; createDotGraph(dotFormat, "DotGraph"); }这将创建
dotsource.dot和DotGraph.pdf表示您指定的目录中的立方图。 请记住：您只需要更改代码中两个参数的值：cfgProp和TEMP_DIR。希望有所帮助。
我在这里回答了类似的问题： 从Java调用Graphviz点
您可以使用Graphviz Java API类，它是Runtime.exec（）的包装器，如果您在与Java App相同的服务器上具有点二进制文件。
如果您没有在服务器上安装点，或者如果您使用的是Google AppEngine等无法在本地安装点二进制文件的环境，那么您可以使用Graphviz Server ，一个基于Java的轻量级HTTP服务器，您仍然需要安装运行Graphviz Server的服务器上的点二进制文件。
以下是使用Graphviz Java API类的代码示例
// graphTypeis one of: pdf, svg, png, etc... private static final String TEMP_PATH = "/tmp/graph."; private File generateGraph(String dot, String graphType) { GraphViz gv = new GraphViz(); gv.readString(dot); File out = new File(TEMP_PATH + graphType); // Linux gv.writeGraphToFile( gv.getGraph( gv.getDotSource(), graphType ), out ); return out; }