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http断点续传简单实现(java)

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/* h^>kjMM  
**SiteFileFetch.java ok'0Byo  
*/ !{s $V2_  
package NetFox; e=Kv[R'(M  
import java.io.*; ;0xCrE{l"  
import java.net.*; Vw9^otJu  
8Mg4y1)RU  
#X"\:yN  
public class SiteFileFetch extends Thread { VR_+/,~  
Njq#@*>[p  
; Z61|@Y  
SiteInfoBean siteInfoBean = null; //文件信息Bean )gR14a  
long[] nStartPos; //开始位置 lIzJO$8cM  
long[] nEndPos; //结束位置 uh#PZ xnP  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 K;6K!6J:[  
long nFileLength; //文件长度 ) 0AE*S  
boolean bFirst = true; //是否第一次取文件 y%TR2CvT  
boolean bStop = false; //停止标志 =oT@h 9VI  
File tmpFile; //文件下载的临时信息 I6y&6g  
DataOutputStream output; //输出到文件的输出流 r=L9x/r  
H gNUr5p  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) $'9r=#EH  
public SiteFileFetch(SiteInfoBean bean) throws IOException <?qmB }Y  
{ gSR&CnqZ<  
siteInfoBean = bean; w,3`Xq@  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); _5U Fml9  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); {K3\S 0L  
if(tmpFile.exists ()) #yr19i ?  
{ tx5_e [  
bFirst = false; .j}u'!LKul  
read_nPos(); .[ 1A  
} i'e^[oZ  
else kP;:s  
{ c_ygwO3.Q  
nStartPos = new long[bean.getNSplitter()]; f!LZT!y  
nEndPos = new long[bean.getNSplitter()]; 4#2iL+   
}  b 1[U 9  
~d5"<`<^o  
{]D!@87  
oSa FmP  
} Z7.)[ ;  
>D:S)"  
'd U$QO  
public void run() 3:Z(tM&-O  
{ &/JnAfmYqt  
//获得文件长度 ?sS'T7r v  
//分割文件 7abq3OK+`  
//实例FileSplitterFetch 29qQ3M?  
//启动FileSplitterFetch线程 W^=89I4]  
//等待子线程返回 bLV@Ts  
try{ 2{V|  
if(bFirst) ~:t2@z4p  
{ 3@"VS_;?  
nFileLength = getFileSize(); _ZS<zQ'  
if(nFileLength == -1) A+F-r_]}db  
{ 4l$8lYi  
System.err.println("File Length is not known!"); HJcZ~5jf  
} so8-e  
else if(nFileLength == -2) .ERO*Tj  
{ $Ilr.6';  
System.err.println("File is not access!"); Y 4714  
} ZDDwh&h  
else ^@19cU?q  
{ P)\f\yb  
for(int i=0;i<nStartPos.length;i++) 8U(a&G6gn  
{ f:UN~z'yr  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); a<o0B{7{BM  
} FN,uD:a  
for(int i=0;i<nEndPos.length-1;i++) qt:->yiq+  
{ .N'UnKz  
nEndPos = nStartPos[i+1]; 3)-#yOr  
} )xK!i.  
nEndPos[nEndPos.length-1] = nFileLength; 2 sOc]L:9  
} C {,d4KG  
} j?mJ1J5  
f7W=x6Z4  
y(S0 2v>l  
//启动子线程 aLq;a  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0jzA\$oD  
for(int i=0;i<nStartPos.length;i++) 'H9~rq7  
{ 5;Z~+$1  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $_ i41f[  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lz*2wGI9  
nStartPos,nEndPos,i); n$?oZ *;  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JQ1VCG  
fileSplitterFetch.start(); ;8v5 qz  
}  {Eb6.  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cn<kl^!Q-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -s1VlS/  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GGuLxc?(  
nEndPos = " + nFileLength); z[rB/ |2  
// fileSplitterFetch[nPos.length-1].start(); W9D)QIqbvW  
\wCL)t.cX  
4<Y?#bm'  
//等待子线程结束 [K KoEZ  
//int count = 0; QezK&iJg  
//是否结束while循环 :Rn9rdX  
boolean breakWhile = false; Cf N; `  
F)IP~BE-k  
G~]BC#nB_  
while(!bStop) |eqDT,4  
{ ~h/U ;Da  
write_nPos(); !v`=EF.  
Utility.sleep(500); o (zg_!P  
breakWhile = true; 8HOmWQS  
]5\vYk  
h CiblM  
for(int i=0;i<nStartPos.length;i++) GND[f}  
{ 6uyf  
if(!fileSplitterFetch.bDownOver) qSd $$L^  
{ U&XoT-p$L  
breakWhile = false; 4HJrR^  
break; 'FhnSNT(4=  
} &M!:,B  
} c>SeOnf  
if(breakWhile) 8{YxUD  
break; nGVqVSxKT  
 #L)rz u  
bq O"k t  
//count++; &}cie"\L  
//if(count>4) -ZB"Yg$l  
// siteStop(); F*4+7$E0B  
} B (falmXJ  
v`&Z.9!Tz^  
)R4<* /C:w  
System.err.println("文件下载结束!"); ]`prDw'  
} [XXN0+ /  
catch(Exception e){e.printStackTrace ();} @2gMtf?<  
} .IXwa,  
g8Z14'Ke  
sFQ|lU"n  
//获得文件长度 K^H t$04  
public long getFileSize() Ie"R,,c   
{ ={^#E?  
int nFileLength = -1; 2XHk}M|  
try{ S2)S/ nf  
URL url = new URL(siteInfoBean.getSSiteURL()); ,k!a3"4+TJ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &}O!l'  
httpConnection.setRequestProperty("User-Agent","NetFox"); {rZ"cUm  
(Y([^N q  
y~7lug  
int responseCode=httpConnection.getResponseCode(); wY#mL1dF  
if(responseCode>=400) l'QR2r7&.  
{ d]E vC>  
processErrorCode(responseCode); w>u Z$/  
return -2; //-2 represent access is error R6;>RRU_  
} B! V{.p  
}=a4uCE  
fP58$pwu  
String sHeader; - (1\ `g07  
jm\#($gl=  
I0K!Kcu5Iu  
for(int i=1;;i++) )\vHIXnfJ1  
{ BA,6f?ktXS  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p'~5[JR:  
//Utility.log(in.readLine()); G:`Jrh  
sHeader=httpConnection.getHeaderFieldKey(i);  c^s>  
if(sHeader!=null) \F~Cbj+'Nu  
{ r%d 11[z  
if(sHeader.equals("Content-Length")) Q/)ok$A&  
{ +E|ouFI  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KVxb"|[  
break; e"#D){k#  
} ; ,jLtl  
} 8"mW!M  
else aG_O N0g  
break; !m(L0YH  
} x9l0UD*+g  
} @T1+b"TC  
catch(IOException e){e.printStackTrace ();} +wozjjc  
catch(Exception e){e.printStackTrace ();} ?i2Wst  
siYRRr  
(M,VwwN  
Utility.log(nFileLength); ih |Ky+!  
aGb. Lh9  
Xj~EVD  
return nFileLength; f~nt!$  
} 2 BX GVo  
,Bw)n,  
8`2<g0V2  
//保存下载信息(文件指针位置) qlITQKGG  
private void write_nPos() nDB 2>J  
{ P3tG#cJ  
try{ "%''k~UD 4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;'QY<,p[e  
output.writeInt(nStartPos.length); ywynx<Wg  
for(int i=0;i<nStartPos.length;i++) igB rmaY'  
{ dP7Vs a+  
// output.writeLong(nPos); #z!Hb&Qi\  
output.writeLong(fileSplitterFetch.nStartPos); U?mf^'RE  
output.writeLong(fileSplitterFetch.nEndPos); $KWYe{#  
} D`:d'ow~KQ  
output.close(); 76A>^Bs\/  
} ()M@3={R  
catch(IOException e){e.printStackTrace ();} '&:1?i)  
catch(Exception e){e.printStackTrace ();} @ Rx6 >52>  
} FaE#\Q  
M*|VLOo=v  
$dh4T";  
//读取保存的下载信息(文件指针位置) $@_t5?n``F  
private void read_nPos() 0w(T^G hZ  
{ \D U^idp#  
try{ "WbVCT'i  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Kka8cG  
int nCount = input.readInt(); @>fO;*  
nStartPos = new long[nCount]; a=*ALd_&0  
nEndPos = new long[nCount]; p/k<wCm6  
for(int i=0;i<nStartPos.length;i++) 6L,lq;  
{ /pN'K5@  
nStartPos = input.readLong(); jc&/}o$K  
nEndPos = input.readLong(); q)V1{B@  
} QGr\I/Y  
input.close(); 8VuZ,!WH#  
} >bA$SN  
catch(IOException e){e.printStackTrace ();} b-BM"~N'  
catch(Exception e){e.printStackTrace ();} _+\:OB[Y  
} i#RElH  
O}MZ-/z=o~  
~mK-8U4>K,  
private void processErrorCode(int nErrorCode) k%]DT.cE  
{ Du^x=;  
System.err.println("Error Code : " + nErrorCode); n</k/Mk}  
} ) \-96 xd  
ZD)0P=%  
#7]o6  
//停止文件下载  ,v*p  
public void siteStop() 4`8IFK  
{ M'umoZmW0  
bStop = true; lk_s!<ni  
for(int i=0;i<nStartPos.length;i++) uNe}"hs  
fileSplitterFetch.splitterStop(); 7|QGY7Tf  
QB/7/PW{H\  
_Z+jQFKJ\8  
} \E$1lc  
} S5~`T7Ra  
//负责部分文件的抓取 ua`6M  
**FileSplitterFetch.java MSZ!W(7,<  
*/ 731h ~x!u  
package NetFox; B2~f;zy`  
~reQV6oQua  
)L |tn  
import java.io.*; ;TL(w7vK  
import java.net.*; {*QvC g?  
,`<^F:xl  
>`7OcjLg  
public class FileSplitterFetch extends Thread { S3u yn78hI  
qyg*n>nt  
Fweh =v  
String sURL; //File URL ~ HK1X  
long nStartPos; //File Snippet Start Position w]};0v&\~s  
long nEndPos; //File Snippet End Position #)GW}U]X  
int nThreadID; //Thread's ID $sEB'>:  
boolean bDownOver = false; //Downing is over ku{XW8  
boolean bStop = false; //Stop identical > P<z |8  
FileAccessI fileAccessI = null; //File Access interface S dIGU[fm  
r\(v+cd  
}{ n\tzR  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LZ~2=Y< U(  
{ [ njx7d  
this.sURL = sURL; |d $1wr  
this.nStartPos = nStart; 3->,So0Y  
this.nEndPos = nEnd; F9MR5O"  
nThreadID = id; k/G7.)C  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FZiZg;  
} 3brb*gI_b  
ZB828T3  
Q[M (Wqg  
public void run() "H>.':c"+3  
{ 0$tjNy e  
while(nStartPos < nEndPos && !bStop) 9C_*3?6  
{ \e<mSR  
\a"i7Caa  
VCjq3/[_  
try{ cTM$ZNin  
URL url = new URL(sURL); k({2yc#RD&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i;c'P}[K  
httpConnection.setRequestProperty("User-Agent","NetFox"); - %|P  
String sProperty = "bytes="+nStartPos+"-"; q]px(  
httpConnection.setRequestProperty("RANGE",sProperty); a mqOxb  
Utility.log(sProperty); j'+ELKQ  
}'%^jt[3  
wa!zv^;N*  
InputStream input = httpConnection.getInputStream(); z!$gVWG  
//logResponseHead(httpConnection); S?L#N  
IAf$]Fh  
RU0i#suiz  
byte[] b = new byte[1024]; GM](=|F  
int nRead; &y7 0  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a9=>r  
{ *(G&B\  
nStartPos += fileAccessI.write(b,0,nRead); CM9XPr  
//if(nThreadID == 1) 7rcA[)<'  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T7 {<arL$  
} ?q _^Rj$  
qe$33f*  
zsDocR   
Utility.log("Thread " + nThreadID + " is over!"); QdDObqVdy  
bDownOver = true;  `?|Rc  
//nPos = fileAccessI.write (b,0,nRead); :Hk_8J  
} O|I+],  
catch(Exception e){e.printStackTrace ();} bKMWWJf*'  
} f2yq8/J8.  
} gfde#T)S  
7X}TB\N1  
jH>8bXQqZ  
//打印回应的头信息 }_}KVI  
public void logResponseHead(HttpURLConnection con) l$a?A[M$  
{ $W&:(&  
for(int i=1;;i++) #op:/j  
{ q$gz_nVq,b  
String header=con.getHeaderFieldKey(i); -#.< 12M  
if(header!=null) S/4r\6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XWUP=D~  
Utility.log(header+" : "+con.getHeaderField(header)); pYo=oI  
else M-J<n>hl  
break; JJ ?I>S N!  
} 0C$8g Y*  
} 6Ps.E  
+;Cr];b3  
M0L&~p_F  
public void splitterStop() :et#0!  
{ c~imE%  
bStop = true; kz B\'m,l  
} E]I$}>k  
~_>cM c  
rrqQCn9  
} ObG=>WPJa  
>&U @f  
oC*=JJe,  
/* V`#.7uUP  
**FileAccess.java W:`#% :C  
*//文件访问(定位,写) y('k`>C  
package NetFox; hmC*^"C>U=  
import java.io.*; TL0[@rr4  
SZhOm  
!'G~k+  
public class FileAccessI implements Serializable{ ]< XR]FHx)  
g(Yb^'X/  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V'G Ju  
RandomAccessFile oSavedFile; K j3?ve~  
long nPos; 9Uf j  
i47j lyH  
;H'gT+t<c  
public FileAccessI() throws IOException H8{ol6wc)6  
{ iW%8/$  
this("",0); W!T"m)S  
} By)u-)g9  
h-#1U3d  
P7.'kX9  
public FileAccessI(String sName,long nPos) throws IOException +B}0=Ex$t  
{ o0bM=njok  
oSavedFile = new RandomAccessFile(sName,"rw"); T{+Z(L  
this.nPos = nPos; bBc[bc>R  
oSavedFile.seek(nPos); QDx$==Fo  
} XH}'w9VynR  
=u[k1s?  
2`G OJ,$  
public synchronized int write(byte[] b,int nStart,int nLen) %]2, &  
{ $za8"T*I  
int n = -1; Az;t"  
try{ r|u MovnV  
oSavedFile.write(b,nStart,nLen); Jl3g{a  
n = nLen; iB[~U3  
} G fEX>  
catch(IOException e) cy yVg!+  
{ p Z: F:  
e.printStackTrace (); BZ!v%4^9  
} #Lv2Zoi>G  
u&mS8i}  
-i yyn ^|  
return n; aFz5leD  
} jRSUp E8  
l vMlL5t  
KGH/^!u+R  
} W\&8au ds  
mpPdG  
U4aU}1RKz  
/* #P l~R  
**SiteInfoBean.java N ,8/Y  
*/ nD5 gP  
package NetFox; p$Ox'A4  
>Cw<BIF  
if|+EN%  
public class SiteInfoBean {  ks$JP6  
s<qe,' Y  
#]nx!*JNZ  
private String sSiteURL; //Site's URL )OiT{-m  
private String sFilePath; //Saved File's Path C{gyj}5  
private String sFileName; //Saved File's Name x=ul&|^7D  
private int nSplitter; //Count of Splited Downloading File wr[,  
R" ;x vo*  
Oo"^%F~%  
public SiteInfoBean() uwz)($~bp  
{//nSplitter的缺省值为5 Vn*tp bz  
//default value of nSplitter is 5 oE#d,Z  
this("","","",5); rE}%KsZ  
} QUu}Xg:  
4"gM<z  
v?KC%  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;\f gF@  
{ T:5fc2Ngv  
sSiteURL= sURL; { ^cV lC_  
sFilePath = sPath; +=O5YR!{  
sFileName = sName; tmQH|'>>  
this.nSplitter = nSpiltter; 0g0i4IV  
xuqv6b.  
F(tx)V ~T3  
} DRcNdO/1E  
Ney/[3 A  
C?lcGt!H  
public String getSSiteURL() 8_{X1bj  
{ V5UF3'3;}  
return sSiteURL; a(l29>  
} zd @m~V  
9I}-[|`u  
wK?vPS  
public void setSSiteURL(String value) \O2Rhz  
{ $<}$DH_Y  
sSiteURL = value; IZpP[hov  
} XD.)Dl8  
 C uB`CI  
Xu%'Z".>:  
public String getSFilePath() <sBbT `  
{ 0yD9SJn  
return sFilePath; }H^+A77v  
} E=nIRG|g  
<J) ]mh dm  
#d6)#:uss  
public void setSFilePath(String value) nAv#?1cjz  
{ ? m DI#~)  
sFilePath = value; 1q7|OWFT  
} .+$ Q<L  
A1O' |7X  
M/b Sud?@%  
public String getSFileName() 8Vr%n2M  
{ 6 (]Dh;gC  
return sFileName; l3)} qu  
} hgPa6Kd  
k>;`FFQU>  
ZrpU <   
public void setSFileName(String value) *\ R ]NV  
{ EJMM9(DQ7  
sFileName = value; F3On?x)  
} MTuV^0%jD  
~%&LTX0s|  
,E S0NA  
public int getNSplitter() -t!~%_WCv  
{ Va"0>KX  
return nSplitter; J')o|5S1N  
} ag [ZW  
)_YX DU  
:CG`t?N9M  
public void setNSplitter(int nCount) marQNZ  
{ p`olCp'  
nSplitter = nCount; $V -~Bu-  
} 6' k<+IR  
} =^M/{51j  
DX#Nf""Pw  
A8muQuj]~~  
/* Ni9/}bb  
**Utility.java 9+Np4i@  
*/ %~4M+r6T  
package NetFox; 0q()|y?}  
.s?L^Z^  
8W*%aOi5+  
public class Utility { ]C!gQq2'a  
]E5o1eeg  
XWBA^|-N  
public Utility() G|bT9f$  
{ 0yk]o5a++  
@a! #G  
xG~P+n7t5$  
} $0W|26;  
d[iQ` YW5  
//线程睡眠 8I=2lK  
public static void sleep(int nSecond) ` 'DmDg  
{ 5%Y3 Kwyy  
try{ pC#E_*49  
Thread.sleep(nSecond); ; 5*&xz  
} IPS4C[v  
catch(Exception e) Y`~Ut:fZ  
{ T^zXt?  
e.printStackTrace (); sA+ }TNhq  
} (d(CT;  
} 1KU! tL  
AP3a;4Z#  
//日志 LP.]9ut  
public static void log(String sMsg) cn3#R.G~  
{ fBU`k_  
System.err.println(sMsg); `}p0VmD{NE  
} { a =#B)6  
mVj9, q0  
3/P1!:g9  
public static void log(int sMsg) 34f?6K1c  
{ #$.;'#u'so  
System.err.println(sMsg); D, k6$`  
} >R'F,  
} .#EFLXs  
p'Y^ X  
(^ J I%>  
/* M`0V~P`^  
**TestMethod.java atj(eg  
*/ d9k0F OR1  
package NetFox; &5>Kl}7  
YX!iL6?~  
q v-8)MSr  
public class TestMethod { irZ])a  
F/ ]2G^-  
M$ wC=b  
public TestMethod() <;lkUU(WT2  
{ ///xx/weblogic60b2_win.exe \UA[  
try{ kBS9tKBWg  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =0 #O U  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pd?M f=>#  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 59LG{R2  
fileFetch.start(); Ao 'l"-  
}  -uS!\  
catch(Exception e){e.printStackTrace ();} 1Yq!~8  
`Gs9Xmc|  
'B |JAi?  
} H8=N@l  
GC-5X`Sq  
`>o{P/HN  
public static void main(String[] args) a .#)G[*  
{ Cp\6W[2+B  
new TestMethod(); 7g^]:3f!   
} /PVk{3  
} : 6jbt:  
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