Java 打印功能 [英] Java Printing Functions

问题描述

我需要帮助在另一个类的这个 java 应用程序中编写打印函数.

函数和printAll我认为是对的，另一个函数肯定是错误的.

public void printAll() {迭代器迭代器 = 值()；while (iterator.hasNext())System.out.println(iterator.next().toString());}//打印来自给定供应商的所有 StockItems 的目录，//按排序顺序(按 SKU 排序).公共无效打印(字符串供应商){迭代器迭代器 = 值()；if (dictionary.getItem(SKU).getVendor() == vendor)System.out.println(tmp.toString());}

我将在下面写下整个函数，用于解决此问题所需的部分.

import data_structures.*;导入 java.util.Iterator;公共类产品查找{DictionaryADT字典;私人 int maxSize;公共 ProductLookup(int maxSize, DictionaryADT 字典) {这(最大尺寸)；this.dictionary = 字典；}//构造函数.没有无参数构造函数或默认大小公共产品查找(int maxSize){this.maxSize = maxSize;}//向字典中添加一个新的 StockItempublic void addItem(String SKU, StockItem item) {字典.插入(SKU，项目)；}//返回与给定 SKU 关联的 StockItem，如果是//在 ProductLookup 中，如果不是，则为 null.公共 StockItem getItem(字符串 SKU){如果(SKU == null)返回空；返回字典.getValue(SKU);}//返回与给定 SKU 值关联的零售价.//-.01 如果该项目不在字典中公共浮动 getRetail(字符串 SKU){if (!dictionary.contains(SKU))返回(浮动)-.01；返回 getItem(SKU).getRetail();}公共浮动 getCost(String SKU) {if (!dictionary.contains(SKU))返回(浮动)-.01；返回 getItem(SKU).getCost();}//返回项目的描述，如果字典中没有，则返回 null.公共字符串getDescription(字符串SKU){if (!dictionary.contains(SKU))返回空；返回 getItem(SKU).getDescription();}//如果是，则删除与 SKU 关联的 StockItem//在产品查找中.如果找到则返回 true 并且//删除，否则为假.公共布尔删除项目(字符串 SKU){如果(SKU == null)返回假；返回字典.删除(SKU)；}//打印所有 StockItems 及其关联的目录//价格，按排序顺序(按 SKU 排序).公共无效printAll(){迭代器迭代器 = 值()；while (iterator.hasNext())System.out.println(iterator.next().toString());}//打印来自给定供应商的所有 StockItems 的目录，//按排序顺序(按 SKU 排序).公共无效打印(字符串供应商){迭代器迭代器 = 值()；if (dictionary.getItem(SKU).getVendor() == vendor)System.out.println(tmp.toString());}//SKU 键的迭代器.公共迭代器键(){返回dictionary.keys();}//StockItem 值的迭代器.公共迭代器值(){返回字典.值()；}}

由于没有实际看到 DictionaryADT 会让人感到困惑，所以我将其包含在此处.

包data_structures;导入 java.util.Iterator;导入 java.util.NoSuchElementException;公共接口 DictionaryADT<K,V>{//如果字典有一个对象，则返回真//输入它，否则为假.公共布尔包含(K 键)；//将给定的键/值对添加到字典中.退货//如果字典已满，或者键是重复的，则为 false.//如果添加成功，则返回 true.公共布尔插入(K 键，V 值)；//删除由 key 参数标识的键/值对.//如果找到并删除了键/值对，则返回 true，//否则为假.公共布尔删除(K 键)；//返回与参数键关联的值.退货//如果未找到键或字典为空，则为 null.public V getValue(K key);//返回与参数值关联的键.退货//如果在字典中找不到该值，则为 null.如果更多//存在一个匹配给定值的键，返回//第一个找到.公共 K getKey(V 值);//返回当前存储的键/值对的数量//在字典中公共整数大小()；//如果字典处于最大容量，则返回 true公共布尔 isFull();//如果字典为空则返回真公共布尔 isEmpty();//将 Dictionary 对象返回到空状态.公共无效清除()；//以升序返回字典中键的迭代器//排序顺序.迭代器必须是快速失败的.公共迭代器<K>键()；//返回字典中值的迭代器.这//值的顺序必须与键的顺序匹配.//迭代器必须是快速失败的.公共迭代器值()；}

解决方案

如果DictionaryADT是一个有所有实际实现的类，那么你需要调用

我相信你在 DictionaryADT 里面有 Map ，比如

public Collection值(){返回字典.值()；}

获取key，Iterator改为Set

public Set键(){返回字典.keySet();//返回设置，请执行所有设置操作.}

我相信这就是您正在寻找的.

谢谢，班纳特.

I need help writing the printing functions in this java application of another class.

The functions are with printAll I think is right and the other function is definitely wrong.

public void printAll() {
    Iterator<StockItem> iterator = values();
    while (iterator.hasNext())
        System.out.println(iterator.next().toString());
}

// Prints a directory of all StockItems from the given vendor, 
// in sorted order (ordered by SKU).
public void print(String vendor) {
    Iterator<StockItem> iterator = values();
    if (dictionary.getItem(SKU).getVendor() == vendor)
        System.out.println(tmp.toString());
}

The entire function I will write down below for the parts that are needed for this problem.

import data_structures.*;
import java.util.Iterator;

public class ProductLookup {


DictionaryADT<String,StockItem> dictionary;
private int maxSize;

public ProductLookup(int maxSize, DictionaryADT<String,StockItem> dictionary) {
    this(maxSize);
    this.dictionary = dictionary;
}

// Constructor.  There is no argument-less constructor, or default size
public ProductLookup(int maxSize) {
    this.maxSize = maxSize;
}

// Adds a new StockItem to the dictionary
public void addItem(String SKU, StockItem item) {
    dictionary.insert(SKU,item);
}

// Returns the StockItem associated with the given SKU, if it is
// in the ProductLookup, null if it is not.
public StockItem getItem(String SKU) {
    if (SKU == null)
        return null;
    return dictionary.getValue(SKU);
}

// Returns the retail price associated with the given SKU value.
// -.01 if the item is not in the dictionary
public float getRetail(String SKU) {
    if (!dictionary.contains(SKU))
        return (float) -.01;
    return getItem(SKU).getRetail();
}

public float getCost(String SKU) {
    if (!dictionary.contains(SKU))
        return (float) -.01;
    return getItem(SKU).getCost();
}

// Returns the description of the item, null if not in the dictionary.
public String getDescription(String SKU) {
    if (!dictionary.contains(SKU))
        return null;
    return getItem(SKU).getDescription();
}

// Deletes the StockItem associated with the SKU if it is
// in the ProductLookup.  Returns true if it was found and
// deleted, otherwise false.  
public boolean deleteItem(String SKU) {
    if (SKU == null)
        return false;
    return dictionary.remove(SKU);
}

// Prints a directory of all StockItems with their associated
// price, in sorted order (ordered by SKU).
public void printAll() {
    Iterator<StockItem> iterator = values();
    while (iterator.hasNext())
        System.out.println(iterator.next().toString());
}

// Prints a directory of all StockItems from the given vendor, 
// in sorted order (ordered by SKU).
public void print(String vendor) {
    Iterator<StockItem> iterator = values();
    if (dictionary.getItem(SKU).getVendor() == vendor)
        System.out.println(tmp.toString());
}

// An iterator of the SKU keys.
public Iterator<String> keys() {
    return dictionary.keys();
}

// An iterator of the StockItem values.    
public Iterator<StockItem> values() {
     return dictionary.values();
}
}

Since it was confusing without actually seeing DictionaryADT I will include it here.

package data_structures;

import java.util.Iterator;
import java.util.NoSuchElementException;


public interface DictionaryADT<K,V> {

// Returns true if the dictionary has an object identified by
// key in it, otherwise false.
public boolean contains(K key);

// Adds the given key/value pair to the dictionary.  Returns
// false if the dictionary is full, or if the key is a duplicate.
// Returns true if addition succeeded.
public boolean insert(K key, V value);

// Deletes the key/value pair identified by the key parameter.
// Returns true if the key/value pair was found and removed,
// otherwise false.
public boolean remove(K key);

// Returns the value associated with the parameter key.  Returns
// null if the key is not found or the dictionary is empty.
public V getValue(K key);

// Returns the key associated with the parameter value.  Returns
// null if the value is not found in the dictionary.  If more
// than one key exists that matches the given value, returns the
// first one found.
public K getKey(V value);

// Returns the number of key/value pairs currently stored
// in the dictionary
public int size();

// Returns true if the dictionary is at max capacity
public boolean isFull();

// Returns true if the dictionary is empty
public boolean isEmpty();

// Returns the Dictionary object to an empty state.
public void clear();

// Returns an Iterator of the keys in the dictionary, in ascending
// sorted order.  The iterator must be fail-fast.
public Iterator<K> keys();

// Returns an Iterator of the values in the dictionary.  The
// order of the values must match the order of the keys.
// The iterator must be fail-fast.
public Iterator<V> values();
}

解决方案

If DictionaryADT is a class with all the actual implementation, then you need to call

I believe you have Map inside DictionaryADT then, something like

public Collection<StockItem> values() {
    return dictionary.values(); 
}

to get the keys, Iterator is changed to Set

public Set<String> keys() {
    return dictionary.keySet(); // return Set, Please perform all the set opetations.
}

I believe this what you are looking for.

Thanks, Bennet.

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