JAVA学习提高之－－－－JAVA开源项目之操作csv文件

JAVA操作csv文件的开源项目很多，如想查可看下面链接
http://sourceforge.net/search/?type_of_search=soft&words=csv

看到网上有人认为不错的一个，地址是：
http://opencsv.sourceforge.net/

下载源码地址：http://sourceforge.net/project/showfiles.php?group_id=148905&package_id=164539
最新的是1.8版的，因为最近项目要用到CSV文件的读写，所以对有关内容进行学习，主要是对CSV文件分析器类的学习，下面只是发布出来的API，具体的类下载的资源里面有。

具体思路：因为csv file本身可以当作文件文件来操作，所以只需使用BufferedReader的readLine方法即可读取一行了。

2. opencsv
4. AnOpenSourceJavacsvlibraryundercommercial-friendlylicense...committedtochangingtheworld,onecommaatatime...
5. Whatisopencsv?
7. opencsvisaverysimplecsv(comma-separatedvalues)parserlibraryforJava.ItwasdevelopedbecauseallofcurrentcsvparsersI'vecomeacrossdon'thavecommercial-friendlylicenses.
8. WherecanIgetit?
10. SourceandbinariesareavailablefromSourceforge.
11. Whatfeaturesdoesopencsvsupport?
13. opencsvsupportsallthebasiccsv-typethingsyou'relikelytowanttodo:
15. *Arbitrarynumbersofvaluesperline
16. *Ignoringcommasinquotedelements
17. *Handlingquotedentrieswithembeddedcarriagereturns(ieentriesthatspanmultiplelines)
18. *Configurableseparatorandquotecharacters(orusesensibledefaults)
19. *Readalltheentriesatonce,oruseanIteratorstylemodel
20. *CreatingcsvfilesfromString[](ie.automaticescapingofembeddedquotechars)
22. HowdoIreadandparseaCSVfile?
24. IfyouwanttouseanIteratorstylepattern,youmightdosomethinglikethis:
26. CSVReaderreader=newCSVReader(newFileReader("yourfile.csv"));
27. String[]nextLine;
28. while((nextLine=reader.readNext())!=null){
29. //nextLine[]isanarrayofvaluesfromtheline
30. System.out.println(nextLine[0]+nextLine[1]+"etc...");
31. }
34. Or,ifyoumightjustwanttoslurpthewholelotintoaList,justcallreadAll()...
36. CSVReaderreader=newCSVReader(newFileReader("yourfile.csv"));
37. ListmyEntries=reader.readAll();
40. whichwillgiveyouaListofString[]thatyoucaniterateover.Ifallelsefails,checkouttheJavadoc.
41. CanIusemyownseparatorsandquotecharacters?
43. Yes.Thereareconstructorsthatcaterforsupplyingyourownseparatorandquotecharacters.Sayyou'reusingatabforyourseparator,youcandosomethinglikethis:
45. CSVReaderreader=newCSVReader(newFileReader("yourfile.csv"),'\t');
48. Andifyousinglequotedyourescapedcharactersratherthandoublequotethem,youcanusethethreeargconstructor:
50. CSVReaderreader=newCSVReader(newFileReader("yourfile.csv"),'\t','\'');
53. Youmayalsoskipthefirstfewlinesofthefileifyouknowthatthecontentdoesn'tstarttilllaterinthefile.So,forexample,youcanskipthefirsttwolinesbydoing:
55. CSVReaderreader=newCSVReader(newFileReader("yourfile.csv"),'\t','\'',2);
58. CanIwritecsvfileswithopencsv?
60. Yes.ThereisaCSVWriterinthesamepackagethatfollowsthesamesemanticsastheCSVReader.Forexample,towriteatabseparatedfile:
62. CSVWriterwriter=newCSVWriter(newFileWriter("yourfile.csv"),'\t');
63. //feedinyourarray(orconvertyourdatatoanarray)
64. String[]entries="first#second#third".split("#");
65. writer.writeNext(entries);
66. writer.close();
69. Ifyou'dprefertouseyourownquotecharacters,youmayusethethreeargversionoftheconstructor,whichtakesaquotecharacter(orfeelfreetopassinCSVWriter.NO_QUOTE_CHARACTER).
71. Youcanalsocustomisethelineterminatorsusedinthegeneratedfile(whichishandywhenyou'reexportingfromyourLinuxwebapplicationtoWindowsclients).Thereisaconstructorargumentforthispurpose.
72. CanIdumpoutSQLtablestoCSV?
74. Yesyoucan.SeanSullivanaddedaneatfeaturetoCSVWritersoyoucanpasswriteAll()aResultSet.
76. java.sql.ResultSetmyResultSet=....
77. writer.writeAll(myResultSet,includeHeaders);
80. IsthereawaytobindmyCSVfiletoalistofJavabeans?
82. Yesthereis.KyleMilleraddedanewsetofclassestoallowyoutobindaCSVfiletoalistofJavaBeansbasedoncolumnname,columnposition,oracustommappingstrategy.Youcanfindthenewclassesintheau.com.bytecode.opencsv.beanpackage.Here'showyoucanmaptoajavabeanbasedonthefieldpositionsinyourCSVfile:
84. ColumnPositionMappingStrategystrat=newColumnPositionMappingStrategy();
85. strat.setType(YourOrderBean.class);
86. String[]columns=newString[]{"name","orderNumber","id"};//thefieldstobinddoinyourJavaBean
87. strat.setColumnMapping(columns);
89. CsvToBeancsv=newCsvToBean();
90. Listlist=csv.parse(strat,yourReader);
93. Formoredetailedexamples,checkoutthetestcasesforeachoftheavailablemappingstrategiesunderthe/test/au/com/bytecode/opencsv/bean/.
94. CanIuseopencsvinmycommercialapplications?
96. Yes.opencsvisavailableunderacommercial-friendlyApache2.0license.Youarefreetoincludeitinyourcommericialapplicationswithoutanyfeeorcharge,andyouarefreetomodifyittosuityourcircumstances.Tofindoutmoredetailsofthelicense,readtheApache2.0licenseagreement.
97. CanIgetthesource?Moreexamplecode?
99. Yes.ThedownloadfromtheSourceForgepageincludesthefullsourceinthe/srcdirectory.It'sonefile,sogocrazy.Thereisalsoasampleaddressbookcsvreaderinthe/examplesdirectory.Andforextramarks,there'saJUnittestsuiteinthe/testdirectory.
100. Whomaintainsopencsv?
102. opencsvwasdevelopedinacoupleofhoursbyGlenSmith.Youcanreadhisblogformoreinfoandcontactdetails.
104. Ifyou'vefoundabug,youcanreportitontheprojectpageatSourceforge.Pleasepostasamplefilethatdemonstratesyourissue.Forbonusmarks,postapatchtoo.:-)

对应的方法为：

1. packageau.com.bytecode.opencsv;
3. /**
4. Copyright2005BytecodePtyLtd.
6. LicensedundertheApacheLicense,Version2.0(the"License");
7. youmaynotusethisfileexceptincompliancewiththeLicense.
8. YoumayobtainacopyoftheLicenseat
10. http://www.apache.org/licenses/LICENSE-2.0
12. Unlessrequiredbyapplicablelaworagreedtoinwriting,software
13. distributedundertheLicenseisdistributedonan"ASIS"BASIS,
14. WITHOUTWARRANTIESORCONDITIONSOFANYKIND,eitherexpressorimplied.
15. SeetheLicenseforthespecificlanguagegoverningpermissionsand
16. limitationsundertheLicense.
17. */
19. importjava.io.BufferedReader;
20. importjava.io.IOException;
21. importjava.io.Reader;
22. importjava.util.ArrayList;
23. importjava.util.List;
25. /**
26. *AverysimpleCSVreaderreleasedunderacommercial-friendlylicense.
27. *
28. *@authorGlenSmith
29. *
30. */
31. publicclassCSVReader{
33. privateBufferedReaderbr;
35. privatebooleanhasNext=true;
37. privatecharseparator;
39. privatecharquotechar;
41. privateintskipLines;
43. privatebooleanlinesSkiped;
45. /**Thedefaultseparatortouseifnoneissuppliedtotheconstructor.*/
46. publicstaticfinalcharDEFAULT_SEPARATOR=',';
48. /**
49. *Thedefaultquotecharactertouseifnoneissuppliedtothe
50. *constructor.
51. */
52. publicstaticfinalcharDEFAULT_QUOTE_CHARACTER='"';
54. /**
55. *Thedefaultlinetostartreading.
56. */
57. publicstaticfinalintDEFAULT_SKIP_LINES=0;
59. /**
60. *ConstructsCSVReaderusingacommafortheseparator.
61. *
62. *@paramreader
63. *thereadertoanunderlyingCSVsource.
64. */
65. publicCSVReader(Readerreader){
66. this(reader,DEFAULT_SEPARATOR);
67. }
69. /**
70. *ConstructsCSVReaderwithsuppliedseparator.
71. *
72. *@paramreader
73. *thereadertoanunderlyingCSVsource.
74. *@paramseparator
75. *thedelimitertouseforseparatingentries.
76. */
77. publicCSVReader(Readerreader,charseparator){
78. this(reader,separator,DEFAULT_QUOTE_CHARACTER);
79. }
83. /**
84. *ConstructsCSVReaderwithsuppliedseparatorandquotechar.
85. *
86. *@paramreader
87. *thereadertoanunderlyingCSVsource.
88. *@paramseparator
89. *thedelimitertouseforseparatingentries
90. *@paramquotechar
91. *thecharactertouseforquotedelements
92. */
93. publicCSVReader(Readerreader,charseparator,charquotechar){
94. this(reader,separator,quotechar,DEFAULT_SKIP_LINES);
95. }
97. /**
98. *ConstructsCSVReaderwithsuppliedseparatorandquotechar.
99. *
100. *@paramreader
101. *thereadertoanunderlyingCSVsource.
102. *@paramseparator
103. *thedelimitertouseforseparatingentries
104. *@paramquotechar
105. *thecharactertouseforquotedelements
106. *@paramline
107. *thelinenumbertoskipforstartreading
108. */
109. publicCSVReader(Readerreader,charseparator,charquotechar,intline){
110. this.br=newBufferedReader(reader);
111. this.separator=separator;
112. this.quotechar=quotechar;
113. this.skipLines=line;
114. }
116. /**
117. *ReadstheentirefileintoaListwitheachelementbeingaString[]of
118. *tokens.
119. *
120. *@returnaListofString[],witheachString[]representingalineofthe
121. *file.
122. *
123. *@throwsIOException
124. *ifbadthingshappenduringtheread
125. */
126. publicListreadAll()throwsIOException{
128. ListallElements=newArrayList();
129. while(hasNext){
130. String[]nextLineAsTokens=readNext();
131. if(nextLineAsTokens!=null)
132. allElements.add(nextLineAsTokens);
133. }
134. returnallElements;
136. }
138. /**
139. *Readsthenextlinefromthebufferandconvertstoastringarray.
140. *
141. *@returnastringarraywitheachcomma-separatedelementasaseparate
142. *entry.
143. *
144. *@throwsIOException
145. *ifbadthingshappenduringtheread
146. */
147. publicString[]readNext()throwsIOException{
149. StringnextLine=getNextLine();
150. returnhasNext?parseLine(nextLine):null;
151. }
153. /**
154. *Readsthenextlinefromthefile.
155. *
156. *@returnthenextlinefromthefilewithouttrailingnewline
157. *@throwsIOException
158. *ifbadthingshappenduringtheread
159. */
160. privateStringgetNextLine()throwsIOException{
161. if(!this.linesSkiped){
162. for(inti=0;i<skipLines;i++){
163. br.readLine();
164. }
165. this.linesSkiped=true;
166. }
167. StringnextLine=br.readLine();
168. if(nextLine==null){
169. hasNext=false;
170. }
171. returnhasNext?nextLine:null;
172. }
174. /**
175. *ParsesanincomingStringandreturnsanarrayofelements.
176. *
177. *@paramnextLine
178. *thestringtoparse
179. *@returnthecomma-tokenizedlistofelements,ornullifnextLineisnull
180. *@throwsIOExceptionifbadthingshappenduringtheread
181. */
182. privateString[]parseLine(StringnextLine)throwsIOException{
184. if(nextLine==null){
185. returnnull;
186. }
188. ListtokensOnThisLine=newArrayList();
189. StringBuffersb=newStringBuffer();
190. booleaninQuotes=false;
191. do{
192. if(inQuotes){
193. //continuingaquotedsection,reappendnewline
194. sb.append("\n");
195. nextLine=getNextLine();
196. if(nextLine==null)
197. break;
198. }
199. for(inti=0;i<nextLine.length();i++){
201. charc=nextLine.charAt(i);
202. if(c==quotechar){
203. //thisgetscomplex...thequotemayendaquotedblock,orescapeanotherquote.
204. //doa1-charlookahead:
205. if(inQuotes//weareinquotes,thereforetherecanbeescapedquotesinhere.
206. &&nextLine.length()>(i+1)//thereisindeedanothercharactertocheck.
207. &&nextLine.charAt(i+1)==quotechar){//..andthatchar.isaquotealso.
208. //wehavetwoquotecharsinarow==onequotechar,soconsumethembothand
209. //putoneonthetoken.wedo*not*exitthequotedtext.
210. sb.append(nextLine.charAt(i+1));
211. i++;
212. }else{
213. inQuotes=!inQuotes;
214. //thetrickycaseofanembeddedquoteinthemiddle:a,bc"d"ef,g
215. if(i>2//notonthebeginingoftheline
216. &&nextLine.charAt(i-1)!=this.separator//notatthebeginingofanescapesequence
217. &&nextLine.length()>(i+1)&&
218. nextLine.charAt(i+1)!=this.separator//notattheendofanescapesequence
219. ){
220. sb.append(c);
221. }
222. }
223. }elseif(c==separator&&!inQuotes){
224. tokensOnThisLine.add(sb.toString());
225. sb=newStringBuffer();//startworkonnexttoken
226. }else{
227. sb.append(c);
228. }
229. }
230. }while(inQuotes);
231. tokensOnThisLine.add(sb.toString());
232. return(String[])tokensOnThisLine.toArray(newString[0]);
234. }
236. /**
237. *Closestheunderlyingreader.
238. *
239. *@throwsIOExceptioniftheclosefails
240. */
241. publicvoidclose()throwsIOException{
242. br.close();
243. }
245. }

1. packageau.com.bytecode.opencsv;
3. /**
4. Copyright2005BytecodePtyLtd.
6. LicensedundertheApacheLicense,Version2.0(the"License");
7. youmaynotusethisfileexceptincompliancewiththeLicense.
8. YoumayobtainacopyoftheLicenseat
10. http://www.apache.org/licenses/LICENSE-2.0
12. Unlessrequiredbyapplicablelaworagreedtoinwriting,software
13. distributedundertheLicenseisdistributedonan"ASIS"BASIS,
14. WITHOUTWARRANTIESORCONDITIONSOFANYKIND,eitherexpressorimplied.
15. SeetheLicenseforthespecificlanguagegoverningpermissionsand
16. limitationsundertheLicense.
17. */
19. importjava.io.IOException;
20. importjava.io.PrintWriter;
21. importjava.io.Reader;
22. importjava.io.Writer;
23. importjava.math.BigDecimal;
24. importjava.sql.Clob;
25. importjava.sql.ResultSet;
26. importjava.sql.ResultSetMetaData;
27. importjava.sql.SQLException;
28. importjava.sql.Time;
29. importjava.sql.Timestamp;
30. importjava.sql.Types;
31. importjava.text.SimpleDateFormat;
32. importjava.util.Iterator;
33. importjava.util.List;
35. /**
36. *AverysimpleCSVwriterreleasedunderacommercial-friendlylicense.
37. *
38. *@authorGlenSmith
39. *
40. */
41. publicclassCSVWriter{
43. privateWriterrawWriter;
45. privatePrintWriterpw;
47. privatecharseparator;
49. privatecharquotechar;
51. privatecharescapechar;
53. privateStringlineEnd;
55. /**Thecharacterusedforescapingquotes.*/
56. publicstaticfinalcharDEFAULT_ESCAPE_CHARACTER='"';
58. /**Thedefaultseparatortouseifnoneissuppliedtotheconstructor.*/
59. publicstaticfinalcharDEFAULT_SEPARATOR=',';
61. /**
62. *Thedefaultquotecharactertouseifnoneissuppliedtothe
63. *constructor.
64. */
65. publicstaticfinalcharDEFAULT_QUOTE_CHARACTER='"';
67. /**Thequoteconstanttousewhenyouwishtosuppressallquoting.*/
68. publicstaticfinalcharNO_QUOTE_CHARACTER='\u0000';
70. /**Theescapeconstanttousewhenyouwishtosuppressallescaping.*/
71. publicstaticfinalcharNO_ESCAPE_CHARACTER='\u0000';
73. /**Defaultlineterminatorusesplatformencoding.*/
74. publicstaticfinalStringDEFAULT_LINE_END="\n";
76. privatestaticfinalSimpleDateFormat
77. TIMESTAMP_FORMATTER=
78. newSimpleDateFormat("dd-MMM-yyyyHH:mm:ss");
80. privatestaticfinalSimpleDateFormat
81. DATE_FORMATTER=
82. newSimpleDateFormat("dd-MMM-yyyy");
84. /**
85. *ConstructsCSVWriterusingacommafortheseparator.
86. *
87. *@paramwriter
88. *thewritertoanunderlyingCSVsource.
89. */
90. publicCSVWriter(Writerwriter){
91. this(writer,DEFAULT_SEPARATOR);
92. }
94. /**
95. *ConstructsCSVWriterwithsuppliedseparator.
96. *
97. *@paramwriter
98. *thewritertoanunderlyingCSVsource.
99. *@paramseparator
100. *thedelimitertouseforseparatingentries.
101. */
102. publicCSVWriter(Writerwriter,charseparator){
103. this(writer,separator,DEFAULT_QUOTE_CHARACTER);
104. }
106. /**
107. *ConstructsCSVWriterwithsuppliedseparatorandquotechar.
108. *
109. *@paramwriter
110. *thewritertoanunderlyingCSVsource.
111. *@paramseparator
112. *thedelimitertouseforseparatingentries
113. *@paramquotechar
114. *thecharactertouseforquotedelements
115. */
116. publicCSVWriter(Writerwriter,charseparator,charquotechar){
117. this(writer,separator,quotechar,DEFAULT_ESCAPE_CHARACTER);
118. }
120. /**
121. *ConstructsCSVWriterwithsuppliedseparatorandquotechar.
122. *
123. *@paramwriter
124. *thewritertoanunderlyingCSVsource.
125. *@paramseparator
126. *thedelimitertouseforseparatingentries
127. *@paramquotechar
128. *thecharactertouseforquotedelements
129. *@paramescapechar
130. *thecharactertouseforescapingquotecharsorescapechars
131. */
132. publicCSVWriter(Writerwriter,charseparator,charquotechar,charescapechar){
133. this(writer,separator,quotechar,escapechar,DEFAULT_LINE_END);
134. }
137. /**
138. *ConstructsCSVWriterwithsuppliedseparatorandquotechar.
139. *
140. *@paramwriter
141. *thewritertoanunderlyingCSVsource.
142. *@paramseparator
143. *thedelimitertouseforseparatingentries
144. *@paramquotechar
145. *thecharactertouseforquotedelements
146. *@paramlineEnd
147. *thelinefeedterminatortouse
148. */
149. publicCSVWriter(Writerwriter,charseparator,charquotechar,StringlineEnd){
150. this(writer,separator,quotechar,DEFAULT_ESCAPE_CHARACTER,lineEnd);
151. }
155. /**
156. *ConstructsCSVWriterwithsuppliedseparator,quotechar,escapecharandlineending.
157. *
158. *@paramwriter
159. *thewritertoanunderlyingCSVsource.
160. *@paramseparator
161. *thedelimitertouseforseparatingentries
162. *@paramquotechar
163. *thecharactertouseforquotedelements
164. *@paramescapechar
165. *thecharactertouseforescapingquotecharsorescapechars
166. *@paramlineEnd
167. *thelinefeedterminatortouse
168. */
169. publicCSVWriter(Writerwriter,charseparator,charquotechar,charescapechar,StringlineEnd){
170. this.rawWriter=writer;
171. this.pw=newPrintWriter(writer);
172. this.separator=separator;
173. this.quotechar=quotechar;
174. this.escapechar=escapechar;
175. this.lineEnd=lineEnd;
176. }
178. /**
179. *WritestheentirelisttoaCSVfile.Thelistisassumedtobea
180. *String[]
181. *
182. *@paramallLines
183. *aListofString[],witheachString[]representingalineof
184. *thefile.
185. */
186. publicvoidwriteAll(ListallLines){
188. for(Iteratoriter=allLines.iterator();iter.hasNext();){
189. String[]nextLine=(String[])iter.next();
190. writeNext(nextLine);
191. }
193. }
195. protectedvoidwriteColumnNames(ResultSetMetaDatametadata)
196. throwsSQLException{
198. intcolumnCount=metadata.getColumnCount();
200. String[]nextLine=newString[columnCount];
201. for(inti=0;i<columnCount;i++){
202. nextLine[i]=metadata.getColumnName(i+1);
203. }
204. writeNext(nextLine);
205. }
207. /**
208. *WritestheentireResultSettoaCSVfile.
209. *
210. *ThecallerisresponsibleforclosingtheResultSet.
211. *
212. *@paramrstherecordsettowrite
213. *@paramincludeColumnNamestrueifyouwantcolumnnamesintheoutput,falseotherwise
214. *
215. */
216. publicvoidwriteAll(java.sql.ResultSetrs,booleanincludeColumnNames)throwsSQLException,IOException{
218. ResultSetMetaDatametadata=rs.getMetaData();
221. if(includeColumnNames){
222. writeColumnNames(metadata);
223. }
225. intcolumnCount=metadata.getColumnCount();
227. while(rs.next())
228. {
229. String[]nextLine=newString[columnCount];
231. for(inti=0;i<columnCount;i++){
232. nextLine[i]=getColumnValue(rs,metadata.getColumnType(i+1),i+1);
233. }
235. writeNext(nextLine);
236. }
237. }
239. privatestaticStringgetColumnValue(ResultSetrs,intcolType,intcolIndex)
240. throwsSQLException,IOException{
242. Stringvalue="";
244. switch(colType)
245. {
246. caseTypes.BIT:
247. Objectbit=rs.getObject(colIndex);
248. if(bit!=null){
249. value=String.valueOf(bit);
250. }
251. break;
252. caseTypes.BOOLEAN:
253. booleanb=rs.getBoolean(colIndex);
254. if(!rs.wasNull()){
255. value=Boolean.valueOf(b).toString();
256. }
257. break;
258. caseTypes.CLOB:
259. Clobc=rs.getClob(colIndex);
260. if(c!=null){
261. value=read(c);
262. }
263. break;
264. caseTypes.BIGINT:
265. caseTypes.DECIMAL:
266. caseTypes.DOUBLE:
267. caseTypes.FLOAT:
268. caseTypes.REAL:
269. caseTypes.NUMERIC:
270. BigDecimalbd=rs.getBigDecimal(colIndex);
271. if(bd!=null){
272. value=""+bd.doubleValue();
273. }
274. break;
275. caseTypes.INTEGER:
276. caseTypes.TINYINT:
277. caseTypes.SMALLINT:
278. intintValue=rs.getInt(colIndex);
279. if(!rs.wasNull()){
280. value=""+intValue;
281. }
282. break;
283. caseTypes.JAVA_OBJECT:
284. Objectobj=rs.getObject(colIndex);
285. if(obj!=null){
286. value=String.valueOf(obj);
287. }
288. break;
289. caseTypes.DATE:
290. java.sql.Datedate=rs.getDate(colIndex);
291. if(date!=null){
292. value=DATE_FORMATTER.format(date);;
293. }
294. break;
295. caseTypes.TIME:
296. Timet=rs.getTime(colIndex);
297. if(t!=null){
298. value=t.toString();
299. }
300. break;
301. caseTypes.TIMESTAMP:
302. Timestamptstamp=rs.getTimestamp(colIndex);
303. if(tstamp!=null){
304. value=TIMESTAMP_FORMATTER.format(tstamp);
305. }
306. break;
307. caseTypes.LONGVARCHAR:
308. caseTypes.VARCHAR:
309. caseTypes.CHAR:
310. value=rs.getString(colIndex);
311. break;
312. default:
313. value="";
314. }
317. if(value==null)
318. {
319. value="";
320. }
322. returnvalue;
324. }
326. privatestaticStringread(Clobc)throwsSQLException,IOException
327. {
328. StringBuffersb=newStringBuffer((int)c.length());
329. Readerr=c.getCharacterStream();
330. char[]cbuf=newchar[2048];
331. intn=0;
332. while((n=r.read(cbuf,0,cbuf.length))!=-1){
333. if(n>0){
334. sb.append(cbuf,0,n);
335. }
336. }
337. returnsb.toString();
338. }
340. /**
341. *Writesthenextlinetothefile.
342. *
343. *@paramnextLine
344. *astringarraywitheachcomma-separatedelementasaseparate
345. *entry.
346. */
347. publicvoidwriteNext(String[]nextLine){
349. if(nextLine==null)
350. return;
352. StringBuffersb=newStringBuffer();
353. for(inti=0;i<nextLine.length;i++){
355. if(i!=0){
356. sb.append(separator);
357. }
359. StringnextElement=nextLine[i];
360. if(nextElement==null)
361. continue;
362. if(quotechar!=NO_QUOTE_CHARACTER)
363. sb.append(quotechar);
364. for(intj=0;j<nextElement.length();j++){
365. charnextChar=nextElement.charAt(j);
366. if(escapechar!=NO_ESCAPE_CHARACTER&&nextChar==quotechar){
367. sb.append(escapechar).append(nextChar);
368. }elseif(escapechar!=NO_ESCAPE_CHARACTER&&nextChar==escapechar){
369. sb.append(escapechar).append(nextChar);
370. }else{
371. sb.append(nextChar);
372. }
373. }
374. if(quotechar!=NO_QUOTE_CHARACTER)
375. sb.append(quotechar);
376. }
378. sb.append(lineEnd);
379. pw.write(sb.toString());
381. }
383. /**
384. *Flushunderlyingstreamtowriter.
385. *
386. *@throwsIOExceptionifbadthingshappen
387. */
388. publicvoidflush()throwsIOException{
390. pw.flush();
392. }
394. /**
395. *Closetheunderlyingstreamwriterflushinganybufferedcontent.
396. *
397. *@throwsIOExceptionifbadthingshappen
398. *
399. */
400. publicvoidclose()throwsIOException{
401. pw.flush();
402. pw.close();
403. rawWriter.close();
404. }
406. }

以下是达人对此API做的测试：
http://blog.csdn.net/lord_is_layuping/archive/2008/02/14/2095766.aspx

我也做了测试，实际上直接调用API中的方法即可，不过还是应该看懂源码，感觉写的不错，对提高水平有很大的帮助，以后在开源项目方面要多看看。。。