Question

我在项目中使用browscap-java。但是初始加载时间太长。

final UserAgentParser parser = new UserAgentService().loadParser();

加载代码耗时约22058ms。

这是我的代码：

 public String[] getAgentInfo() {
    final UserAgentParser parser;
    try {
        parser = new UserAgentService().loadParser();
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    } catch (ParseException e) {
        e.printStackTrace();
        return null;
    }
    final String userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36";
    final Capabilities capabilities = parser.parse(userAgent);
    final String[] agentInfo = new String[6];

    agentInfo[0] = capabilities.getBrowser();
    agentInfo[1] = capabilities.getBrowserType();
    agentInfo[2] = capabilities.getBrowserMajorVersion();
    agentInfo[3] = capabilities.getDeviceType();
    agentInfo[4] = capabilities.getPlatform();
    agentInfo[5] = capabilities.getPlatformVersion();

    return agentInfo;
}

每次使用此功能都会初始化parser。但是parser是不变的，所以我想知道如何重用parser，使parser仅在第一次初始化。

PS：该代码适用于Java Web。

Answer 1

您可以在此方法之外初始化/构建解析器，并将其作为参数传递。这将为您提供一次初始化解析器的灵活性，并通过传递已初始化的解析器多次调用此方法。

public UserAgentParser createUserAgentParser() {
    final UserAgentParser parser;
    try {
        parser = new UserAgentService().loadParser();
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    } catch (ParseException e) {
        e.printStackTrace();
        return null;
    }
    return parser;
 }

 public String[] getAgentInfo(final UserAgentParser parser) {

    final String userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36";
    final Capabilities capabilities = parser.parse(userAgent);
    final String[] agentInfo = new String[6];

    agentInfo[0] = capabilities.getBrowser();
    agentInfo[1] = capabilities.getBrowserType();
    agentInfo[2] = capabilities.getBrowserMajorVersion();
    agentInfo[3] = capabilities.getDeviceType();
    agentInfo[4] = capabilities.getPlatform();
    agentInfo[5] = capabilities.getPlatformVersion();

    return agentInfo;
}

如何在Java中重用没有框架的实例？

1 个答案: