我熟悉python和ruby中的线程，但是我对如何用Java执行它感到有点迷失。
我见过的例子告诉我一些关于Runnable界面的事情，但我不太确定这是如何解决我正在尝试做的事情。
基本上我正在尝试重构网络刮刀以改为使用线程（因此每个网址都由新线程完成）以加快速度。
在ruby中，我只是做一个Thread.new，但我不确定如何（正确！）在java中实现它。
任何人都可以指导我如何做到这一点？ :)非常感谢！
我已经评论了我想在下面外包的块：）
public class Collecting_Description
{
@SuppressWarnings("empty-statement")
public static void main(String[] args) throws FileNotFoundException, IOException
{
FileReader fr = new FileReader("plugin_list.txt");
BufferedReader br = new BufferedReader(fr);
FileWriter fw = new FileWriter("DescriptionOutPut.txt",true);
BufferedWriter bw = new BufferedWriter (fw);
List<String> listOfPlugins = new ArrayList <String>();
listOfPlugins = Collecting_Description.addToListOfPlugins(br, listOfPlugins);
// THIS BLOCK TO BE REFACTORED TO USE THREADING
for (int i=0;i<listOfPlugins.size();i++)
{
System.out.println(listOfPlugins.get(i) + " ("+ i + ") in progress");
String astemp = listOfPlugins.get(i).replace("", "");
try
{
Document doc = Jsoup.connect("https://wordpress.org/plugins/"+ URLDecoder.decode(astemp, "UTF-8")).get();
Elements description = doc.select("div#tab-description");
String context = null;
for(int j=0; j<description.size(); j++)
{
context = context + description.get(j).text();
}
bw.write("[PluginName:{"+ astemp +"},"+ "Description:{"+ context + "}]\n");
}
catch(Exception e)
{
}
}
bw.close();
}
public static List addToListOfPlugins(BufferedReader br,List listOfPlugins) throws IOException {
String line;
while((line = br.readLine())!=null) {
listOfPlugins.add(line);
}
return listOfPlugins;
}
}
编辑：更新代码
package htmlparser.loop;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.net.URLDecoder;
import java.util.ArrayList;
import java.util.List;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.select.Elements;
public class Collecting_Description {
@SuppressWarnings("empty-statement")
public static void main(String[] args) throws FileNotFoundException, IOException {
FileReader fr = new FileReader("plugin_list.txt");
BufferedReader br = new BufferedReader(fr);
FileWriter fw = new FileWriter("DescriptionOutPut.txt",true);
BufferedWriter bw = new BufferedWriter (fw);
List<String> listOfPlugins = new ArrayList <String>();
listOfPlugins = Collecting_Description.addToListOfPlugins(br, listOfPlugins);
// THIS BLOCK TO BE REFACTORED TO USE THREADING
for (int i=0;i<listOfPlugins.size();i++) {
String scrapedHTML = Collecting_Description.scrapeURL(listOfPlugins, i);
// write to file
bw.write(scrapedHTML);
}
bw.close();
}
public static List<String> addToListOfPlugins(BufferedReader br,List<String> listOfPlugins) throws IOException {
String line;
while((line = br.readLine())!=null) {
listOfPlugins.add(line);
}
return listOfPlugins;
}
public static String scrapeURL(List<String> listOfPlugins, int i){
System.out.println(listOfPlugins.get(i) + " ("+ i + ") in progress");
String pluginName = listOfPlugins.get(i).replace("", "");
try {
Document doc = Jsoup.connect("https://wordpress.org/plugins/"+ URLDecoder.decode(pluginName, "UTF-8")).get();
Elements description = doc.select("div#tab-description");
String context = null;
for(int j=0; j<description.size(); j++) {
context = context + description.get(j).text();
}
String returnString = "[PluginName:{"+ pluginName +"},"+ "Description:{"+ context + "}]\n";
return returnString;
}
catch(Exception e){
System.out.println(e);
}
return "Error";
}
}
答案 0 :(得分：0)
至少你可以使用这样的东西：
new Thread() {
// THIS BLOCK TO BE REFACTORED TO USE THREADING
...
...
}.start();
如果您需要传入对象，可以使用类：
public class MyThread implements Runnable {
private List list;
public MyThread(List list) {
this.list = list;
}
public static synchronized void writeToFile() {
// WRITE TO FILE HERE
}
@Override
public void run() {
// DO SOMETHING HERE WITH LIST
...
MyThread.writeToFile();
...
}
}
并做
new MyThread(list).start();
答案 1 :(得分：0)
总的来说，你应该这样做：
以下是一个例子
public static void main(String[] args) throws FileNotFoundException, IOException
{
FileReader fr = new FileReader("plugin_list.txt");
BufferedReader br = new BufferedReader(fr);
final StringBuffer sb = new StringBuffer();
final int counter = 0;
List<String> listOfPlugins = new ArrayList <String>();
final listOfPlugins = Collecting_Description.addToListOfPlugins(br, listOfPlugins);
// THIS BLOCK TO BE REFACTORED TO USE THREADING
for (int i=0;i<listOfPlugins.size();i++)
{
System.out.println(listOfPlugins.get(i) + " ("+ i + ") in progress");
final String astemp = listOfPlugins.get(i).replace("", "");
new Thread(new Runnable() {
@Override
public void run() {
try
{
Document doc = Jsoup.connect("https://wordpress.org/plugins/"+ URLDecoder.decode(astemp, "UTF-8")).get();
Elements description = doc.select("div#tab-description");
String context = null;
for(int j=0; j<description.size(); j++)
{
context = context + description.get(j).text();
}
sb.append("[PluginName:{"+ astemp +"},"+ "Description:{"+ context + "}]\n");
synchronized(Collecting_Description.this) {
counter++;
// Write output util all threads are finished
if (counter >= listOfPlugins.size()) {
FileWriter fw = new FileWriter("DescriptionOutPut.txt",true);
BufferedWriter bw = new BufferedWriter (fw);
bw.write(sb.toString());
bw.close();
}
}
}
catch(Exception e)
{
}
}
).start();
}
}