实现 JobStateReasons API 的Java程序

API 代表应用程序编程接口，它只是一组用于构建和集成应用程序软件以简化应用程序开发以节省时间和金钱的定义和协议。例如，如果我们想使用过去的数据预测不同城市的天气，而不是手动查找和输入所有过去的数据，我们可以使用天气 API 来加快和改进流程。

JobState 是一个打印属性类，而不是一个标识打印作业当前状态的枚举。 JobState 类定义了标准的作业状态值。打印服务实现只需要报告适合特定实现的那些作业状态。它不必报告每个定义的作业状态。 JobStateReasons 属性倾向于增强 JobState 属性，以确保有关给定作业状态下的作业的更多详细信息。

实现： JobStateReasons API 通过Java程序

Java

// Java Program to Implementing JobStateReasons API
  
// Importing java libraries
import java.util.Collection;
import javax.print.attribute.Attribute;
import javax.print.attribute.standard.JobStateReason;
import javax.print.attribute.standard.JobStateReasons;
  
public class GFG {
    private JobStateReasons jobStateReasons;
  
    // Construct a new, empty job state reasons attribute;
    // the underlying hash set has the default initial
    // capacity and load factor
    public GFG()
    {
        jobStateReasons = new JobStateReasons();
    }
  
    // Construct a new job state reasons
    // attribute that contains the same
    // JobStateReason objects as the given collection
    public GFG(Collection collection)
    {
        jobStateReasons = new JobStateReasons(collection);
    }
  
    // Construct a new, empty job state reasons attribute;
    // the underlying hash set has the given
    // initial capacity and the default load
    // factor.
    public GFG(int initialCapacity)
    {
        jobStateReasons
            = new JobStateReasons(initialCapacity);
    }
  
    // Construct a new, empty job state reasons attribute;
    // the underlying hash
    // set has the given initial capacity and load factor
    public GFG(int initialCapacity, float loadFactor)
    {
        jobStateReasons = new JobStateReasons(
            initialCapacity, loadFactor);
    }
  
    // Adds the specified element to this job state reasons
    // attribute if it is not already present.
    public boolean add(JobStateReason o)
    {
        return jobStateReasons.add(o);
    }
  
    // Get the printing attribute class which is to be used
    // as the "category" for this printing attribute value.
  
    public Class getCategory()
    {
        return jobStateReasons.getCategory();
    }
  
    // Get the name of the category of which this attribute
    // value is an instance
    public String getName()
    {
        return jobStateReasons.getName();
    }
  
    // Return true if this set contains the specified
    // element
    public boolean contains(Object obj)
    {
        return jobStateReasons.contains(obj);
    }
  
    // Returns true if the set is empty
    public boolean isEmpty()
    {
        return jobStateReasons.isEmpty();
    }
  
    // Removes the specified element from
    // this set if present
    public boolean remove(Object obj)
    {
        return jobStateReasons.remove(obj);
    }
  
    // Returns the number of elements in set
    public int size() { return jobStateReasons.size(); }
  
    // Removes all elements from this set
    public void clear() { jobStateReasons.clear(); }
  
    // Returns an array containing all of the elements in
    // this set
    public Object[] toArray()
    {
        return jobStateReasons.toArray();
    }
  
    // Main driver function
    public static void main(String args[])
    {
        // Creating object of class
        GFG jobStateReasons = new GFG();
  
        jobStateReasons.add(
            JobStateReason.COMPRESSION_ERROR);
        jobStateReasons.add(
            JobStateReason.JOB_CANCELED_BY_USER);
        jobStateReasons.add(
            JobStateReason.JOB_COMPLETED_WITH_WARNINGS);
        jobStateReasons.add(
            JobStateReason.DOCUMENT_FORMAT_ERROR);
  
        // Display messages
        System.out.println("Category Name: "
                           + jobStateReasons.getName());
        System.out.println();
        System.out.println("The JobStateReasons are: ");
  
        Object[] jobs = (Object[])jobStateReasons.toArray();
  
        for (int i = 0; i < jobs.length; i++) {
            System.out.println((i + 1) + ") " + jobs[i]);
        }
        System.out.println();
  
        jobStateReasons.clear();
        System.out.println(
            "all JobStateReasons are cleared");
  
        if (jobStateReasons.isEmpty())
            System.out.println(
                "jobStateReasons is now empty");
        else
            System.out.println(
                "jobStateReasons is not empty yet");
    }
}

输出：

Category Name: job-state-reasons

The JobStateReasons are: 
1) compression-error
2) document-format-error
3) job-completed-with-warnings
4) job-canceled-by-user

all JobStateReasons are cleared
jobStateReasons is now empty