MANIFEST.MF属性读写

快来打我* 2022-04-08 09:12 303阅读 0赞

本案例完整演示项目 [https://download.csdn.net/download/cs4380/10835284][https_download.csdn.net_download_cs4380_10835284]

# 一、maven打包写入MANIFEST.MF属性 #

本案例采用maven写入，可以采用其他工具写入

在pom.xml文件添加打包插件，早manifestEntries标签中添加自定标签和值

<plugin>
    	<groupId>org.apache.maven.plugins</groupId>
    	<artifactId>maven-jar-plugin</artifactId>
    	<version>2.3.1</version>
    	<configuration>
    		<archive>
    			<manifestEntries>
    				<projectName>
    					项目名称
    				</projectName>
    				<version>
    					v1.0
    				</version>
    			</manifestEntries>
    		</archive>
    	</configuration>
    </plugin>

使用maven打包后获取xxxx.jar文件，打包后MANIFEST.MF新增的属性值

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NzNDM4MA_size_16_color_FFFFFF_t_70][]

# 二、Java读取MANIFEST.MF属性值 #

获取当前jar中MANIFEST.MF文件的属性值，本案例仅提供读取工具类，通过io流获取字符串，获取字符串后解析得到配置。

import org.springframework.util.ClassUtils;
    import org.springframework.util.FileCopyUtils;
    
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.io.StringWriter;
    import java.util.HashMap;
    import java.util.Map;
    import java.util.jar.JarEntry;
    import java.util.jar.JarFile;
    
    /**
     * Manifest 文件操作工具.
     */
    public class ManifestUtil {
    
        /**
         * 获取Manifest文件配置属性值
         *
         * @return
         * @throws IOException
         */
        public static Map<String, String> getManifestProperty() {
            Map<String, String> property = new HashMap<>();
            JarFile jarFile = null;
            String content = "";
            try {
                // 获取jar的运行路径，因linux下jar的路径为”file:/app/.../test.jar!/BOOT-INF/class!/“这种格式，所以需要去掉”file:“和”!/BOOT-INF/class!/“
                String jarFilePath = ClassUtils.getDefaultClassLoader().getResource("").getPath().replace("!/BOOT-INF/classes!/", "");
                if (jarFilePath.startsWith("file")) {
                    jarFilePath = jarFilePath.substring(5);
                }
                // 通过JarFile的getJarEntry方法读取META-INF/MANIFEST.MF
                jarFile = new JarFile(jarFilePath);
                JarEntry entry = jarFile.getJarEntry("META-INF/MANIFEST.MF");
                // 如果读取到MANIFEST.MF文件内容，则转换为string
                if (entry != null) {
                    StringWriter writer = new StringWriter();
                    FileCopyUtils.copy(new InputStreamReader(jarFile.getInputStream(entry), "utf-8"), writer);
                    jarFile.close();
                    content = writer.toString();
                } else {
                    return property;
                }
            } catch (Exception ex) {
                return property;
            } finally {
                try {
                    if (jarFile != null) {
                        jarFile.close();
                    }
                } catch (IOException e) {
                    return property;
                }
            }
            return getProperty(content);
        }
    
        /**
         * 通过字符解析，MANIFEST.MF 文件中的属性值
         *
         * @param content MANIFEST.MF 文件中的字符串
         * @return
         */
        private static Map<String, String> getProperty(String content) {
            Map<String, String> result = new HashMap<>();
            if ("".equals(content.trim())) {
                return result;
            }
            String[] propertys = content.split("\n");
            if (propertys == null || propertys.length == 0) {
                return result;
            }
            String[] temp;
            try {
                for (int i = 0; i < propertys.length; i++) {
                    temp = propertys[i].split(":");
                    if (temp.length == 2) {
                        result.put(temp[0].trim(), temp[1].trim());
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return result;
        }
    }

# 三、功能测试 #

通过 java -jar   xxx.jar 命令执行jar包，输出配置项数据。只有打包后才会生成MANIFEST.MF文件，所有在项目中无法测试

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NzNDM4MA_size_16_color_FFFFFF_t_70 1][]

[https_download.csdn.net_download_cs4380_10835284]: https://download.csdn.net/download/cs4380/10835284
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NzNDM4MA_size_16_color_FFFFFF_t_70]: /images/20220407/58960be826194457a425f2bdbc377872.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NzNDM4MA_size_16_color_FFFFFF_t_70 1]: /images/20220407/5dd109abf38040ecbab9c01ea70c081d.png