Java代码优化：使用Map替换多个if-else语句设置Project请求

Java代码优化：使用Map替换多个if-else语句设置Project请求

在Java开发中，经常会遇到根据不同的条件设置对象属性的情况。例如，在处理Project对象时，需要根据不同的projectId来设置不同的request。如果使用多个if-else语句来实现，代码会变得冗长且难以维护。

原始代码:

public static List<Project> getAllProjectList(List<Project> projects){
        for (Project project : projects){
            if (project.projectId == 2) {
                project.setRequest(getRequest2());
            } else if (project.projectId == 3) {
                project.setRequest(getRequest3());
            } else if (project.projectId == 4) {
                project.setRequest(getRequest4());
            } else if (project.projectId == 5) {
                project.setRequest(getRequest5());
            } else if (project.projectId == 6) {
                project.setRequest(getRequest6());
            } else if (project.projectId == 7) {
                project.setRequest(getRequest7());
            } else if (project.projectId == 8) {
                project.setRequest(getRequest8());
            } else if (project.projectId == 9) {
                project.setRequest(getRequest9());
            } else if (project.projectId == 10) {
                project.setRequest(getRequest10());
            } else if (project.projectId == 11) {
                project.setRequest(getRequest11());
            } else if (project.projectId == 12) {
                project.setRequest(getRequest12());
            } else if (project.projectId == 13) {
                project.setRequest(getRequest13());
            } else if (project.projectId == 14) {
                project.setRequest(getRequest14());
            } else if (project.projectId == 15) {
                project.setRequest(getRequest15());
            } else if (project.projectId == 16) {
                project.setRequest(getRequest16());
            } else if (project.projectId == 17) {
                project.setRequest(getRequest17());
            } else if (project.projectId == 18) {
                project.setRequest(getRequest18());
            } else if (project.projectId == 19) {
                project.setRequest(getRequest19());
            } else if (project.projectId == 21) {
                project.setRequest(getRequest21());
            } else if (project.projectId == 22) {
                project.setRequest(getRequest22());
            } else if (project.projectId == 23) {
                project.setRequest(getRequest23());
            } else if (project.projectId == 24) {
                project.setRequest(getRequest24());
            } else if (project.projectId == 25) {
                project.setRequest(getRequest25());
            } else if (project.projectId == 26) {
                project.setRequest(getRequest26());
            } else if (project.projectId == 27) {
                project.setRequest(getRequest27());
            } else if (project.projectId == 28) {
                project.setRequest(getRequest28());
            } else if (project.projectId == 29) {
                project.setRequest(getRequest29());
            } else if (project.projectId == 30) {
                project.setRequest(getRequest30());
            } else if (project.projectId == 31) {
                project.setRequest(getRequest31());
            } else if (project.projectId == 32) {
                project.setRequest(getRequest32());
            } else if (project.projectId == 33) {
                project.setRequest(getRequest33());
            } else if (project.projectId == 34) {
                project.setRequest(getRequest34());
            } else if (project.projectId == 35) {
                project.setRequest(getRequest35());
            } else if (project.projectId == 36) {
                project.setRequest(getRequest36());
            } else if (project.projectId == 37) {
                project.setRequest(getRequest37());
            } else if (project.projectId == 38) {
                project.setRequest(getRequest38());
            } else if (project.projectId == 1) {
                project.setRequest("");
            } else if (project.projectId == 20) {
                project.setRequest("");
            }

        }
        return projects;
    }
其中project.projectId的类型为long,优化此方法内容：为了优化此方法，可以使用一个Map来存储project.projectId和对应的request的关系，然后通过查询Map来设置project的request。这样可以将多个if-else语句简化为一行代码。

以下是优化后的代码示例：

```java
public static List<Project> getAllProjectList(List<Project> projects) {
    Map<Long, String> requestMap = new HashMap<>();
    requestMap.put(2L, getRequest2());
    requestMap.put(3L, getRequest3());
    requestMap.put(4L, getRequest4());
    // 继续添加其他project.projectId和request的对应关系

    for (Project project : projects) {
        String request = requestMap.getOrDefault(project.projectId, "");
        project.setRequest(request);
    }

    return projects;
}

通过使用Map来存储project.projectId和对应的request的关系，可以避免多个if-else语句的重复判断，提高代码的可读性和可维护性。

总结

使用Map来存储projectId和对应的request的关系，可以有效地优化代码，减少代码量，提高代码的可读性和可维护性。在实际开发中，建议尽量使用Map来处理类似的逻辑，以提高代码质量。