GraphViz爲繪製有向網絡的可視化工具包
使用方法如下：
1）下載安裝http://www.graphviz.org/Download..php。此處說明皆以Windows版本爲平臺。
2）在Java項目中新建類GraphViz，代碼如下，其中需要改的有兩處：一處是TEMP_DIR變量的取值，選擇自己需要保存文件的路徑；二是DOT變量的取值，應該爲安裝GraphViz後路徑中的dot程序文件路徑（此處爲2.30版本默認路徑）
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.io.OutputStreamWriter;
public class GraphViz {
private static String TEMP_DIR = "c:/temp";
private static String DOT = "C:\\Program Files\\Graphviz2.30\\bin\\dot.exe";
private StringBuilder graph = new StringBuilder();
public GraphViz() {
}
public String getDotSource() {
return graph.toString();
}
public void add(String line) {
graph.append(line);
}
public void addln(String line) {
graph.append(line + "\n");
}
public void addln() {
graph.append('\n');
}
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;
}
}
public int writeGraphToFile(byte[] img, String file) {
File to = new File(file);
return writeGraphToFile(img, to);
}
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;
}
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();
String[] args = { DOT, "-T" + type, 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);
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;
}
private File writeDotSourceToFile(String str) throws java.io.IOException {
File temp;
try {
temp = File.createTempFile("graph_", ".dot.tmp", new File(
GraphViz.TEMP_DIR));
FileOutputStream fos=new FileOutputStream(temp.getAbsolutePath());
BufferedWriter br=new BufferedWriter(new OutputStreamWriter(fos,"UTF-8"));
br.write(str);
br.close();
} catch (Exception e) {
System.err.println("Error: I/O error while writing the dot source to temp file!");
return null;
}
return temp;
}
public String start_graph() {
return "digraph G {";
}
public String end_graph() {
return "}";
}
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;
}
}
3）測試使用代碼：
import java.io.File;
public class Proba {
public static void main(String[] args) {
Proba p = new Proba();
p.start();
// p.start2();
}
private void start() {
GraphViz gv = new GraphViz();
gv.addln(gv.start_graph());
gv.addln("rankdir = LR");
gv.addln("encoding=\"UTF-8\"");
gv.addln("node [shape=box,fontname=\"simhei.ttf\",style=filled, fillcolor=\".7 .3 1.0\", color=green, fontsize=10]");
gv.addln("edge[arrowsize= 1.5, arrowhead=\"open\",fontsize=10]");
gv.addln("A -> D->黑體[penwidth=7,color=\"red\"];");
gv.addln("A -> C;");
gv.addln("計算機->C->B;");
gv.addln(gv.end_graph());
System.out.println(gv.getDotSource());
String type = "gif";
// String type = "dot";
// String type = "fig"; // open with xfig
// String type = "pdf";
// String type = "ps";
// String type = "svg"; // open with inkscape
// String type = "png";
// String type = "plain";
File out = new File("c:\\temp\\out." + type);
gv.writeGraphToFile(gv.getGraph(gv.getDotSource(), type), out);
}
private void start2() {
String input = "c:/temp/simple.txt";
GraphViz gv = new GraphViz();
gv.readSource(input);
System.out.println(gv.getDotSource());
String type = "gif";
// String type = "dot";
// String type = "fig"; // open with xfig
// String type = "pdf";
// String type = "ps";
// String type = "svg"; // open with inkscape
// String type = "png";
// String type = "plain";
File out = new File("c:/temp/out." + type);
gv.writeGraphToFile(gv.getGraph(gv.getDotSource(), type), out);
}
}
運行界面爲：
