• 日期: 2027-02-25
  • 标签: 科技

这个问题的代码实现因为方案不同而不同，下面提供两个实现方案：

方案一：使用第三方库

可以使用第三方库，例如jAutoUpdate，它可以帮助我们自动更新应用程序。这个库支持Java Web Start、Swing、JavaFX和Android等多种平台的自动更新。

以下是使用jAutoUpdate自动更新的示例代码：

import de.schlichtherle.util.*;
import de.schlichtherle.util.zip.*;
import de.schlichtherle.xml.*;
import de.schlichtherle.xml.GenericDescriptor.*;
import java.io.*;
import java.net.*;
import java.util.*;
import javax.swing.*;
import org.apache.commons.codec.binary.*;
import org.apache.commons.io.*;
import org.apache.commons.lang3.*;
import org.apache.commons.lang3.exception.*;
import org.dom4j.*;
import org.dom4j.io.*;
import org.jdom.*;
import org.jdom.input.*;
import org.jdom.output.*;
import org.xml.sax.*;

public class AutoUpdater {
    private static final String UPDATE_URL = "http://www.example.com/update.xml";
    private static final String APP_PATH = ".";
    private static final String APP_FILE = "myapp.jar";
    private static final String APP_CLASS_NAME = "com.example.Main";
    private static final String UPDATE_FILE = "update.zip";
    private static final String UPDATE_DESC_FILE = "update.xml";
    private static final String UPDATE_INFO_FILE = "update_info.xml";
    private static final String UPDATE_CHECK_FILE = "update_check.xml";
    private static final String UPDATE_TEMP_PATH = System.getProperty("java.io.tmpdir") + "myapp_update/";

    public static void main(String[] args) {
        try {
            String version = getVersion();
            String updateCheckUrl = UPDATE_URL + "?" + UUID.randomUUID().toString();
            File updateCheckFile = getFile(UPDATE_TEMP_PATH + UPDATE_CHECK_FILE);
            FileUtils.copyURLToFile(new URL(updateCheckUrl), updateCheckFile);
            String updateVersion = getUpdateVersion(updateCheckFile);
            if (StringUtils.isNotEmpty(updateVersion) && !version.equals(updateVersion)) {
                downloadUpdate(updateCheckFile);
                String updateFilePath = UPDATE_TEMP_PATH + UPDATE_FILE;
                File updateFile = getFile(updateFilePath);
                unzipUpdate(updateFilePath, UPDATE_TEMP_PATH);
                String updateDescFilePath = UPDATE_TEMP_PATH + UPDATE_DESC_FILE;
                GenericDescriptor updateDesc = getUpdateDesc(updateDescFilePath);
                updateApp(updateFile, updateDesc);
                JOptionPane.showMessageDialog(null, "The application has been updated. Please restart the application.");
                System.exit(0);
            } else {
                Class.forName(APP_CLASS_NAME).getMethod("main", String[].class).invoke(null, (Object) args);
            }
        } catch (Throwable t) {
            t.printStackTrace();
            String message = ExceptionUtils.getStackTrace(t);
            JOptionPane.showMessageDialog(null, message, "Error", JOptionPane.ERROR_MESSAGE);
        }
    }

    private static String getVersion() throws Exception {
        String appFilePath = APP_PATH + "/" + APP_FILE;
        Manifest manifest = new JarFile(appFilePath).getManifest();
        String version = manifest.getMainAttributes().getValue("Implementation-Version");
        return version;
    }

    private static String getUpdateVersion(File updateCheckFile) throws Exception {
        SAXBuilder builder = new SAXBuilder();
        Document document = builder.build(updateCheckFile);
        Element root = document.getRootElement();
        String updateVersion = root.getChildText("version");
        return updateVersion;
    }

    private static void downloadUpdate(File updateCheckFile) throws Exception {
        SAXBuilder builder = new SAXBuilder();
        Document document = builder.build(updateCheckFile);
        Element root = document.getRootElement();
        String updateUrl = root.getChildText("url");
        String updateFilePath = UPDATE_TEMP_PATH + UPDATE_FILE;
        FileUtils.copyURLToFile(new URL(updateUrl), getFile(updateFilePath));
    }

    private static void unzipUpdate(String updateFilePath, String updateTempPath) throws Exception {
        ZipFile zipFile = new ZipFile(updateFilePath);
        Enumeration<? extends ZipEntry> entries = zipFile.entries();
        while (entries.hasMoreElements()) {
            ZipEntry entry = entries.nextElement();
            String entryName = entry.getName();
            if (entry.isDirectory()) {
                getFile(updateTempPath + entryName).mkdirs();
            } else {
                InputStream inputStream = zipFile.getInputStream(entry);
                FileOutputStream outputStream = new FileOutputStream(getFile(updateTempPath + entryName));
                IOUtils.copy(inputStream, outputStream);
                IOUtils.closeQuietly(inputStream);
                IOUtils.closeQuietly(outputStream);
            }
        }
    }

    private static GenericDescriptor getUpdateDesc(String updateDescFilePath) throws Exception {
        FileInputStream inputStream = new FileInputStream(getFile(updateDescFilePath));
        InputSource inputSource = new InputSource(inputStream);
        GenericDescriptor updateDesc = new GenericDescriptor();
        updateDesc.read(inputSource);
        IOUtils.closeQuietly(inputStream);
        return updateDesc;
    }

    private static void updateApp(File updateFile, GenericDescriptor updateDesc) throws Exception {
        String appFilePath = APP_PATH + "/" + APP_FILE;
        String backupFilePath = APP_PATH + "/" + APP_FILE + ".bak";
        FileUtils.copyFile(new File(appFilePath), new File(backupFilePath));
        FileUtils.copyFile(updateFile, new File(appFilePath));
        updateDesc.write(new FileOutputStream(APP_PATH + "/META-INF/update.xml"), "UTF-8");
    }

    private static File getFile(String path) throws Exception {
        File file = new File(path);
        file.getParentFile().mkdirs();
        file.createNewFile();
        return file;
    }
}

需要注意的是，上述代码假设更新文件是一个zip压缩包，其中包含一个update.xml文件和一个更新的应用程序文件。update.xml文件包含了更新的描述信息，例如版本号、更新的URL等。更新的应用程序文件是一个jar文件，可以包含多个类和资源文件。

方案二：手动实现

手动实现应用程序自动更新的过程需要以下步骤：

  1. 获取当前应用程序的版本号。
  2. 向服务器请求更新信息的URL。
  3. 解析服务器返回的更新信息，获取最新版本号和更新的URL等信息。
  4. 如果最新版本号大于当前版本号，则下载更新文件。
  5. 解压更新文件。
  6. 备份旧的应用程序文件。
  7. 将更新的应用程序文件复制到应用程序目录下。
  8. 重启应用程序。

以下是手动实现自动更新的示例代码：

import java.io.*;
import java.net.*;
import java.util.*;
import java.util.zip.*;
import javax.swing.*;

public class AutoUpdater {
    private static final String UPDATE_URL = "http://www.example.com/update.xml";
    private static final String APP_PATH = ".";
    private static final String APP_FILE = "myapp.jar";
    private static final String APP_CLASS_NAME = "com.example.Main";
    private static final String UPDATE_FILE = "update.zip";
    private static final String UPDATE_TEMP_PATH = System.getProperty("java.io.tmpdir") + "myapp_update/";

    public static void main(String[] args) {
        try {
            String version = getVersion();
            String updateCheckUrl = UPDATE_URL + "?" + UUID.randomUUID().toString();
            String updateCheckResult = downloadUpdateCheck(updateCheckUrl);
            String updateVersion = getUpdateVersion(updateCheckResult);
            if (updateVersion != null && compareVersion(updateVersion, version) > 0) {
                String updateUrl = getUpdateUrl(updateCheckResult);
                downloadUpdate(updateUrl);
                String updateFilePath = UPDATE_TEMP_PATH + UPDATE_FILE;
                unzipUpdate(updateFilePath, UPDATE_TEMP_PATH);
                backupApp();
                updateApp(updateFilePath);
                JOptionPane.showMessageDialog(null, "The application has been updated. Please restart the application.");
                System.exit(0);
            } else {
                Class.forName(APP_CLASS_NAME).getMethod("main", String[].class).invoke(null, (Object) args);
            }
        } catch (Throwable t) {
            t.printStackTrace();
            String message = t.getMessage();
            JOptionPane.showMessageDialog(null, message, "Error", JOptionPane.ERROR_MESSAGE);
        }
    }

    private static String getVersion() throws Exception {
        String appFilePath = APP_PATH + "/" + APP_FILE;
        Manifest manifest = new JarFile(appFilePath).getManifest();
        String version = manifest.getMainAttributes().getValue("Implementation-Version");
        return version;
    }

    private static String downloadUpdateCheck(String updateCheckUrl) throws Exception {
        HttpURLConnection connection = (HttpURLConnection) new URL(updateCheckUrl).openConnection();
        connection.setRequestMethod("GET");
        connection.setConnectTimeout(5000);
        connection.setReadTimeout(5000);
        connection.connect();
        InputStream inputStream = connection.getInputStream();
        String result = readStream(inputStream);
        inputStream.close();
        connection.disconnect();
        return result;
    }

    private static String readStream(InputStream inputStream) throws Exception {
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int length;
        while ((length = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, length);
        }
        String result = new String(outputStream.toByteArray(), "UTF-8");
        outputStream.close();
        return result;
    }

    private static String getUpdateVersion(String updateCheckResult) throws Exception {
        int index = updateCheckResult.indexOf("<version>");
        if (index != -1) {
            int endIndex = updateCheckResult.indexOf("</version>", index);
            if (endIndex != -1) {
                String version = updateCheckResult.substring(index + "<version>".length(), endIndex);
                return version;
            }
        }
        return null;
    }

    private static String getUpdateUrl(String updateCheckResult) throws Exception {
        int index = updateCheckResult.indexOf("<url>");
        if (index != -1) {
            int endIndex = updateCheckResult.indexOf("</url>", index);
            if (endIndex != -1) {
                String url = updateCheckResult.substring(index + "<url>".length(), endIndex);
                return url;
            }
        }
        return null;
    }

    private static int compareVersion(String version1, String version2) {
        String[] v1 = version1.split("\\.");
        String[] v2 = version2.split("\\.");
        int length = Math.max(v1.length, v2.length);
        for (int i = 0; i < length; i++) {
            int n1 = i < v1.length ? Integer.parseInt(v1[i]) : 0;
            int n2 = i < v2.length ? Integer.parseInt(v2[i]) : 0;
            if (n1 != n2) {
                return n1 > n2 ? 1 : -1;
            }
        }
        return 0;
    }

    private static void downloadUpdate(String updateUrl) throws Exception {
        HttpURLConnection connection = (HttpURLConnection) new URL(updateUrl).openConnection();
        connection.setRequestMethod("GET");
        connection.setConnectTimeout(5000);
        connection.setReadTimeout(5000);
        connection.connect();
        InputStream inputStream = connection.getInputStream();
        FileOutputStream outputStream = new FileOutputStream(getFile(UPDATE_TEMP_PATH + UPDATE_FILE));
        byte[] buffer = new byte[1024];
        int length;
        while ((length = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, length);
        }
        inputStream.close();
        outputStream.close();
        connection.disconnect();
    }

    private static void unzipUpdate(String updateFilePath, String updateTempPath) throws Exception {
        ZipFile zipFile = new ZipFile(updateFilePath);
        Enumeration<? extends ZipEntry> entries = zipFile.entries();
        while (entries.hasMoreElements()) {
            ZipEntry entry = entries.nextElement();
            String entryName = entry.getName();
            if (entry.isDirectory()) {
                getFile(updateTempPath + entryName).mkdirs();
            } else {
                InputStream inputStream = zipFile.getInputStream(entry);
                FileOutputStream outputStream = new FileOutputStream(getFile(updateTempPath + entryName));
                byte[] buffer = new byte[1024];
                int length;
                while ((length = inputStream.read(buffer)) != -1) {
                    outputStream.write(buffer, 0, length);
                }
                inputStream.close();
                outputStream.close();
            }
        }
        zipFile.close();
    }

    private static void backupApp() throws Exception {
        String appFilePath = APP_PATH + "/" + APP_FILE;
        String backupFilePath = APP_PATH + "/" + APP_FILE + ".bak";
        FileUtils.copyFile(new File(appFilePath), new File(backupFilePath));
    }

    private static void updateApp(String updateFilePath) throws Exception {
        String appFilePath = APP_PATH + "/" + APP_FILE;
        File appFile = new File(appFilePath);
        appFile.delete();
        FileUtils.copyFile(new File(updateFilePath), appFile);
    }

    private static File getFile(String path) throws Exception {
        File file = new File(path);
        file.getParentFile().mkdirs();
        file.createNewFile();
        return file;
    }
}

需要注意的是，上述代码假设更新文件是一个zip压缩包，其中包含一个更新的应用程序文件。更新的应用程序文件是一个jar文件，可以包含多个类和资源文件。更新信息使用XML格式保存，例如：

<update>
    <version>1.1.0</version>
    <url>http://www.example.com/myapp_1.1.0.jar</url>
</update>
APPH5+APP版本自动更新的实现代码

原文地址: https://www.cveoy.top/t/topic/bS9Q 著作权归作者所有。请勿转载和采集!

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