如何找到以准确单词开头的字符串

Question

我在gwt上有一个带有GUI的应用程序。使用此gui，我想要更改(这是一个子问题:如何更好地更改.properties文件(我知道如何使用org.apache.commons.configuration读取属性，但不知道如何编辑(作为字符串或如何.)).properties文件。例如:我编写了以下.properties文件：

################################################################################
# User permissions                                                             #
################################################################################

users = admin, root, guest
users.admin.keywords = admin
users.admin.regexps = test-5, test-7

users.root.keywords = root
users.root.regexps = *

users.guest.keywords = guest
users.guest.regexps = *

那么，如何为管理添加keywords呢？

UPD:这里是我使用的配置类，我想在其中更改配置文件：

    public class Config {

    private static final Config ourInstance = new Config();
    private static final CompositeConfiguration prop = new CompositeConfiguration();

    public static Config getInstance() {
        return ourInstance;
    }

    public Config(){
    }

    public synchronized void load() {
        try {
            prop.addConfiguration(new SystemConfiguration());

            System.out.println("Loading /rules.properties");
            final PropertiesConfiguration p = new PropertiesConfiguration();
            p.setPath("/home/mikhail/bzrrep/DLP/DLPServer/src/main/resources/rules.properties");
            p.load();
            prop.addConfiguration(p);

        } catch (ConfigurationException e) {
            e.printStackTrace();
        }

        final int processors = prop.getInt("server.processors", 1);

        // If you don't see this line - likely config name is wrong
        System.out.println("Using processors:" + processors);
    }

    public void setKeyword(String customerId, String keyword){
        prop.setProperty("users." + customerId + ".keywords", prop.getProperty("users." + customerId + ".keywords") + ", " + keyword);
        prop.
    }

    public void setRegexp(String customerId, String regexp)
    {}
}

Answer 1

试着跟随

Properties prop = new Properties();

        try {
            //set the properties value
            prop.setProperty("users.guest.keywords", "keyword");
            prop.setProperty("users.guest.regexps", "regexps");    
            prop.store(new FileOutputStream("config.properties"), null);

        } catch (IOException ex) {
            ex.printStackTrace();
        }

希望它能帮上忙

Answer 2

负载道具

void getPropertiesFromFile( Properties props, String fileName )
{
    try {
        File file = new File( fileName ) ;
        if (!file.exists())
            return ;

        FileInputStream in = new FileInputStream( file ) ;

        try {
            props.load( in ) ;
        } finally {
            in.close() ;
        }
    } catch (Exception e) {
    }
}

注意:您可能希望不是从文件中加载它们，而是使用classLoader.getResource()加载它们；代码将略有变化。

然后，遍历名称并找到所需的内容。

for (String name : props.keys) {
   if (name.startWith("users.admin.")) {
       String value = props.get(name);
       ...
   }
}

如果要在迭代期间修改道具，则应按以下方式包装props.keys

for (String name : new HashSet(props.keys)) {

做完之后，把它们储存起来

    FileOutputStream fos = null;
    try {
        File file = new File("abc");
        fos = new FileOutputStream(file);
        props.store(fos, null);
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (fos != null) {
            try {
                fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

Answer 3

回答你原来的问题。

boolean String.startsWith(<prefix>)