可設定 Timeout 之 Java Command Line Executor

import java.util.concurrent.TimeoutException;

public class TimeoutCommandLine {

    public static int executeCommandLine(String commandLine, long timeout)
            throws Exception {

        Process process = Runtime.getRuntime().exec(commandLine);

        Worker worker = new Worker(process);

        worker.start();

        try {

            worker.join(timeout);

            if (worker.exit != null) {

                return worker.exit;

            } else {

                throw new TimeoutException();

            }

        } catch (InterruptedException ex) {

            worker.interrupt();

            Thread.currentThread().interrupt();

            throw ex;

        } finally {

            process.destroy();

        }

    }

    private static class Worker extends Thread {

        private final Process process;

        private Integer exit;

        private Worker(Process process) {

            this.process = process;

        }

        public void run() {

            try {

                exit = process.waitFor();

            } catch (InterruptedException ignore) {

                return;

            }

        }

    }

}
使用方式：
TimeoutCommandLine.executeCommandLine("rsh xxxHost hostname", 2000);
設定執行 command rsh xxxHost hostname , 超過 2秒 沒回應即回傳 TimeoutException。

Java Method for Regular Expression

以下 Method 為判斷字串是否符合所設定之 Regular Expression

    /**

     * Get the match result between string and regular expression pattern string

     *

     * @param patternStr - Regular expression pattern string.

     * @param testString - String for testing with match pattern.

     * @return true/false: String is match (true), or is not match (false).

     */

    public static boolean isRegexMatch(String patternStr, String testString) {

        Pattern pattern = Pattern.compile(patternStr);

        Matcher matcher = pattern.matcher(testString);

       

        return matcher.matches();

    }

JSON 與 Map 互轉 (使用 GSON)

import java.lang.reflect.Type;

import java.util.Map;

import com.google.gson.Gson;

import com.google.gson.JsonSyntaxException;

public class JsonUtils {

  

    public static Map<String, Object> fromJson(String json) {

        return fromJson(json, Map.class);

    }

    public static String toJson(Object src) {

        Gson gson = new Gson();

        return gson.toJson(src);

    }

    public static <T> T fromJson(String json, Type typeOfT) {

        Gson gson = new Gson();

        return (T) gson.fromJson(json, typeOfT);

    }

   

    public static boolean isValidJson(String json) {

        try {

            fromJson(json);

            return true;

        } catch(JsonSyntaxException ex) {

            return false;

        }

    }

   

    public static boolean isValidJson(String json, Type typeOfT) {

        try {

            fromJson(json, Map.class);

            return true;

        } catch(JsonSyntaxException ex) {

            return false;

        }

    }

}

使用方式：

[JSON 轉 Map]

Map<String, Object> retMap = JsonUtils.fromJson(jsonData);

傳入 JSON 字串 jsonData ==> JsonUtils.fromJson(jsonData)

回傳型態為 Map<String, Object> 之 map: retMap

[Map 轉 JSON]

String jsonString = JsonUtils.toJson(mapData);

傳入 型態為 Map<String, Object> 之 map mapData ==> JsonUtils.toJson(mapData);

回傳 JSON 字串 jsonString