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  • map

    containsKey方法用来判断Map集合对象中是否包含指定的键名。

    for (Map<String, String> mp : result) {

      for (Map.Entry<String, String> entry : mp.entrySet()) {

        if(mp.containsKey("ciqSampleNo")||mp.containsKey("ciqDeclareNo")){

    interface Entry<K,V> {
            /**
             * Returns the key corresponding to this entry.
             *
             * @return the key corresponding to this entry
             * @throws IllegalStateException implementations may, but are not
             *         required to, throw this exception if the entry has been
             *         removed from the backing map.
             */
            K getKey();
    
            /**
             * Returns the value corresponding to this entry.  If the mapping
             * has been removed from the backing map (by the iterator's
             * <tt>remove</tt> operation), the results of this call are undefined.
             *
             * @return the value corresponding to this entry
             * @throws IllegalStateException implementations may, but are not
             *         required to, throw this exception if the entry has been
             *         removed from the backing map.
             */
            V getValue();
    
            /**
             * Replaces the value corresponding to this entry with the specified
             * value (optional operation).  (Writes through to the map.)  The
             * behavior of this call is undefined if the mapping has already been
             * removed from the map (by the iterator's <tt>remove</tt> operation).
             *
             * @param value new value to be stored in this entry
             * @return old value corresponding to the entry
             * @throws UnsupportedOperationException if the <tt>put</tt> operation
             *         is not supported by the backing map
             * @throws ClassCastException if the class of the specified value
             *         prevents it from being stored in the backing map
             * @throws NullPointerException if the backing map does not permit
             *         null values, and the specified value is null
             * @throws IllegalArgumentException if some property of this value
             *         prevents it from being stored in the backing map
             * @throws IllegalStateException implementations may, but are not
             *         required to, throw this exception if the entry has been
             *         removed from the backing map.
             */
            V setValue(V value);
    
            /**
             * Compares the specified object with this entry for equality.
             * Returns <tt>true</tt> if the given object is also a map entry and
             * the two entries represent the same mapping.  More formally, two
             * entries <tt>e1</tt> and <tt>e2</tt> represent the same mapping
             * if<pre>
             *     (e1.getKey()==null ?
             *      e2.getKey()==null : e1.getKey().equals(e2.getKey()))  &amp;&amp;
             *     (e1.getValue()==null ?
             *      e2.getValue()==null : e1.getValue().equals(e2.getValue()))
             * </pre>
             * This ensures that the <tt>equals</tt> method works properly across
             * different implementations of the <tt>Map.Entry</tt> interface.
             *
             * @param o object to be compared for equality with this map entry
             * @return <tt>true</tt> if the specified object is equal to this map
             *         entry
             */
            boolean equals(Object o);
    
            /**
             * Returns the hash code value for this map entry.  The hash code
             * of a map entry <tt>e</tt> is defined to be: <pre>
             *     (e.getKey()==null   ? 0 : e.getKey().hashCode()) ^
             *     (e.getValue()==null ? 0 : e.getValue().hashCode())
             * </pre>
             * This ensures that <tt>e1.equals(e2)</tt> implies that
             * <tt>e1.hashCode()==e2.hashCode()</tt> for any two Entries
             * <tt>e1</tt> and <tt>e2</tt>, as required by the general
             * contract of <tt>Object.hashCode</tt>.
             *
             * @return the hash code value for this map entry
             * @see Object#hashCode()
             * @see Object#equals(Object)
             * @see #equals(Object)
             */
            int hashCode();
        }
    
        // Comparison and hashing
    
        /**
         * Compares the specified object with this map for equality.  Returns
         * <tt>true</tt> if the given object is also a map and the two maps
         * represent the same mappings.  More formally, two maps <tt>m1</tt> and
         * <tt>m2</tt> represent the same mappings if
         * <tt>m1.entrySet().equals(m2.entrySet())</tt>.  This ensures that the
         * <tt>equals</tt> method works properly across different implementations
         * of the <tt>Map</tt> interface.
         *
         * @param o object to be compared for equality with this map
         * @return <tt>true</tt> if the specified object is equal to this map
         */
        boolean equals(Object o);
    
        /**
         * Returns the hash code value for this map.  The hash code of a map is
         * defined to be the sum of the hash codes of each entry in the map's
         * <tt>entrySet()</tt> view.  This ensures that <tt>m1.equals(m2)</tt>
         * implies that <tt>m1.hashCode()==m2.hashCode()</tt> for any two maps
         * <tt>m1</tt> and <tt>m2</tt>, as required by the general contract of
         * {@link Object#hashCode}.
         *
         * @return the hash code value for this map
         * @see Map.Entry#hashCode()
         * @see Object#equals(Object)
         * @see #equals(Object)
         */
        int hashCode();
    
    }
    Set<Map.Entry<K, V>> entrySet();
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  • 原文地址:https://www.cnblogs.com/hellowzd/p/9625669.html
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