Java 只能使用getter方法一次
我正在从事一个Java项目,在该项目中,我在TextAnalyzer类中使用了下面的getter方法:Java 只能使用getter方法一次,java,Java,我正在从事一个Java项目,在该项目中,我在TextAnalyzer类中使用了下面的getter方法: public Hashtable<String, Double> getTotalFeatureOccurances() { return(feat_occur_total); }//getTotalFeatureOccurances 以下是整个课程: public class TextAnalyzer { TextAnalyzer() { th
public Hashtable<String, Double> getTotalFeatureOccurances() {
return(feat_occur_total);
}//getTotalFeatureOccurances
以下是整个课程:
public class TextAnalyzer {
TextAnalyzer() {
this.feat_occur_total = new Hashtable<String, Double>();
}
public String[][] wordOccurancesCount(String text, Vector<String> features) {
String[][] occur = new String[features.size()][features.size()];
for(int ndx=0; ndx<features.size(); ndx++) {
int count=0;
Pattern p = Pattern.compile("(?:^|\\s+|\\()\\s*(" + features.elementAt(ndx).trim() + ")\\w*(?:,|\\.|\\)|\\s|$)", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.CANON_EQ);
Matcher m = p.matcher(text);
m.usePattern(p);
while(m.find())
count++;
occur[ndx][0] = features.elementAt(ndx);
occur[ndx][1] = String.valueOf(count);
if(this.feat_occur_total.containsKey(features.elementAt(ndx))) {
double temp = this.feat_occur_total.get(features.elementAt(ndx));
temp += count;
this.feat_occur_total.put(features.elementAt(ndx), temp);
}//if
else {
this.feat_occur_total.put(features.elementAt(ndx), Double.valueOf(count));
}//else
}//for
return(occur);
}//word
public Hashtable<String, Double> getTotalFeatureOccurances() {
return(feat_occur_total);
}//getTotalFeatureOccurances
private Hashtable<String, Double> feat_occur_total;
}//TextAnalyzer
公共类文本分析器{
TextAnalyzer(){
this.feat_occurrent_total=新哈希表();
}
公共字符串[][]WordOccuranceCount(字符串文本、向量特征){
字符串[][]出现=新字符串[features.size()][features.size()];
对于(int ndx=0;ndx
清除哈希表。由于返回了对原始变量的引用,因此清除了哈希表本身,而不是副本。因此,再次返回它将返回已清除的哈希表。此:
清除哈希表。由于您返回了对原始变量的引用,因此您清除了哈希表本身,而不是副本。因此,再次返回它将返回已清除的哈希表。您的getter将返回对私有feat\u occurrent\u total
字段的引用,而不是副本。在此之后,TextAnalyzer.feat\u occurrent\u total代码>引用和getter返回的引用引用同一实例
使用从getter返回的引用,该引用将清除顶部的代码段和TextAnalyzer
实例引用的映射。getter将返回对私有feat\u occure\u total
字段的引用,而不是副本。TextAnalyzer.feat\u occure\u total
引用d getter返回的引用引用同一实例
使用从getter返回的引用,该引用清除顶部的代码段和TextAnalyzer
实例引用的映射。顺便说一句,Hashtable已过时-在单线程代码中首选HashMap,或者在其他情况下选择ConcurrentHashMap。这可能只是迂腐,但如果创建Hashtable和ne在你的类中更改私有引用时,它也应该是“最终的”。这向类的用户表明了您的意图,并且最终变量允许编译器执行它可能无法执行的优化。顺便说一句,Hashtable已过时-在单线程代码中更喜欢HashMap,或者在其他情况下更喜欢ConcurrentHashMap。这可能只是迂腐,但如果您创建了Hashtable而从不执行更改类中的私有引用,它也应该是“final”。这向类的用户表明了您的意图,final变量允许编译器执行它可能无法执行的优化。它是一个具有少量t
:)的Hashtable
)巨大的帮助。我没有意识到它返回了对哈希表的引用,很高兴知道。谢谢你的帮助。它是Hashtable
,有点t
:)巨大的帮助。我没有意识到它返回了对哈希表的引用,很高兴知道。谢谢你的帮助。
TextAnalyzer ta = new TextAnalyzer();
feat_occur_cat = ta.wordOccurancesCount(text, features);
feat_occur_total = ta.getTotalFeatureOccurances();
Enumeration<Double> e = feat_occur_total.elements();
while(e.hasMoreElements()) {
System.out.println(e.nextElement());
}//while
feat_occur_total.clear();
feat_occur_total = ta.getTotalFeatureOccurances();
e = feat_occur_total.elements();
System.out.println("\n\nSECOND GET\n\n");
while(e.hasMoreElements()) {
System.out.println(e.nextElement());
}//while
2.0
1.0
5.0
1.0
1.0
3.0
2.0
3.0
SECOND GET
public class TextAnalyzer {
TextAnalyzer() {
this.feat_occur_total = new Hashtable<String, Double>();
}
public String[][] wordOccurancesCount(String text, Vector<String> features) {
String[][] occur = new String[features.size()][features.size()];
for(int ndx=0; ndx<features.size(); ndx++) {
int count=0;
Pattern p = Pattern.compile("(?:^|\\s+|\\()\\s*(" + features.elementAt(ndx).trim() + ")\\w*(?:,|\\.|\\)|\\s|$)", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.CANON_EQ);
Matcher m = p.matcher(text);
m.usePattern(p);
while(m.find())
count++;
occur[ndx][0] = features.elementAt(ndx);
occur[ndx][1] = String.valueOf(count);
if(this.feat_occur_total.containsKey(features.elementAt(ndx))) {
double temp = this.feat_occur_total.get(features.elementAt(ndx));
temp += count;
this.feat_occur_total.put(features.elementAt(ndx), temp);
}//if
else {
this.feat_occur_total.put(features.elementAt(ndx), Double.valueOf(count));
}//else
}//for
return(occur);
}//word
public Hashtable<String, Double> getTotalFeatureOccurances() {
return(feat_occur_total);
}//getTotalFeatureOccurances
private Hashtable<String, Double> feat_occur_total;
}//TextAnalyzer
feat_occur_total.clear();