Java获取系统环境变量和系统属性信息
import java.io.File;import java.io.FileNotFoundException;import java.io.FileWriter;import java.io.IOException;import java.util.Map;import java.util.Properties;import javax.swing.JOptionPane;public class T1 {public static void main(String[] args) throws FileNotFoundException, IOException {StringBuilder sb = new StringBuilder();sb.append("<html>");sb.append("<style>");sb.append("td");sb.append("{");sb.append("font-size:10pt;");sb.append("border:1 solid #5b99c8;font-family:Arial;");sb.append("}");sb.append("th");sb.append("{");sb.append("font-size:12pt;");sb.append("background-color:#8fcae9;");sb.append("border:1 solid #5b99c8;font-family:Arial;");sb.append("}</style>");sb.append("<head>");sb.append("</head>");sb.append("<body bgcolor="#eff7ff">");sb.append("<table border="1" cellpadding="0" cellspacing="0" style="border-collapse:collapse;border:1 solid #5b99c8;" cellpadding=2 cellspacing=0 width='100%'>");// 写表头sb.append("<tr><th colspan='2'>Environment variable</th></tr>");sb.append("<tr><th>key</th><th>value</th></tr>");// 写表内容Map<String,String> envMap = System.getenv();for(String key:envMap.keySet()){String value = envMap.get(key);sb.append("<tr>");sb.append("<td>");sb.append(key);sb.append("</td>");sb.append("<td>");sb.append(value);sb.append("</td>");sb.append("</tr>");}sb.append("</table>");// 写表头sb.append("<table>");sb.append("<tr><th colspan='2'>System Properties</th></tr>");sb.append("<tr><th>key</th><th>value</th></tr>");// 写表内容Properties p = System.getProperties();for(Object key:p.keySet()){String value = p.getProperty(key+"");sb.append("<tr>");sb.append("<td>");sb.append(key);sb.append("</td>");sb.append("<td>");sb.append(value);sb.append("</td>");sb.append("</tr>");}sb.append("</table>");sb.append("</body>");sb.append("</html>");try {File file = new File("环境变量与系统属性信息.html");FileWriter fileWriter = new FileWriter(file);fileWriter.write(sb.toString());fileWriter.flush();fileWriter.close();JOptionPane.showMessageDialog(null, "获取系统环境变量和系统属性成功！"); } catch (IOException e) {JOptionPane.showMessageDialog(null, e.toString());}}}?
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