比较Java中列表映射中的每个对象

Question

我有一个 Java 程序，其 Map 类型<String, Project>包含所有 Project 对象，并且 Project 的每个对象都包含一个相关 Process 对象的列表，即List<Process>.public class Project {    private String name;    private Path path;    private List<Process> processes;        \\ getters and setters follow和public class Process {    private String name;    private String path;    private String flow;        \\getters and setters follow我正在编写一个函数来查找每个（跨所有项目）JaroWinklerDistance之间的字符串距离（使用）。我想出了以下内容：flowProcess    public void compareAllProcesses(Map<String, Project> projects) {        Iterator<Project> projIter1 = projects.values().iterator();        while(projIter1.hasNext()) {            Project proj1 = projIter1.next();            Iterator<Process> procIter1 = proj1.getProcesses().iterator();            while(procIter1.hasNext()) {                Process proc1 = procIter1.next();                Iterator<Project> projIter2 = projects.values().iterator();                while(projIter2.hasNext()) {                    Project proj2 = projIter2.next();                    Iterator<Process> procIter2 = proj2.getProcesses().iterator();                    while(procIter2.hasNext()) {                        Process proc2 = procIter2.next();                        //use JaroWinklerDistance to compare proc1.getFlow() with proc2.getFLow()                    }                }            }        }    }有没有更有效和更优雅的方式来实现这一目标？

Answer 1

List<Process> allProcesses = projects.values()

    .stream()

    .flatMap(p->p.getProcesses().stream());

for (Process currentProcess : allProcesses) {

    for (Process process : allProcesses) {

        //distance calculation

    }

}

Answer 2

也许加一点糖：

    for (Project proj1: projects.values()) {

        for (Process proc1: proj1.getProcesses()) {

            for(Project proj2: projects.values()) {

                for(Process proc2: proj2.getProcesses()) {

                    //use JaroWinklerDistance to compare proc1.getFlow() with proc2.getFLow()

                }

            }

        }

    }

Answer 3

也许与Streams：

projects.values()
        .stream()
        .flatMap(p->p.getProcesses().stream())
        .forEach(proc1 ->  projects.values()
                                   .stream()
                                   .flatMap(p->p.getProcesses().stream())
                                   .forEach(proc2 -> {/*do something with proc1 and proc2*/});