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http断点续传简单实现(java)

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/* ^`iqa-1  
**SiteFileFetch.java ~xPU#m<  
*/ c6-~PKJL  
package NetFox; 9 n0 ?0mk  
import java.io.*; f(S9>c2  
import java.net.*; 94.|l  
Y(mnGaVn  
x_L5NsO:  
public class SiteFileFetch extends Thread { 1egq:bh  
W?TvdeBx  
VcX89c4\  
SiteInfoBean siteInfoBean = null; //文件信息Bean @3*S:;x  
long[] nStartPos; //开始位置 -qyhg-k6  
long[] nEndPos; //结束位置 G'#Uzwo  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 kLE("I:7  
long nFileLength; //文件长度 9u?[{h.`B  
boolean bFirst = true; //是否第一次取文件 }vK8P r%  
boolean bStop = false; //停止标志 ;}B6`v  
File tmpFile; //文件下载的临时信息 S/,)X  
DataOutputStream output; //输出到文件的输出流 ?*AhGza/  
xTnFJ$RK2  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) K]SsEsd  
public SiteFileFetch(SiteInfoBean bean) throws IOException OV2/?  
{ +,xluwv$9  
siteInfoBean = bean; I_k/lwBD  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); n?(sn  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); {Qba`lOkq  
if(tmpFile.exists ()) z&wJ"[nOC  
{ p!/!ZIo  
bFirst = false; L$t.$[~L  
read_nPos(); /Z| K9a  
} u(W>HVEG  
else vC^Ul  
{ QtHK`f>4#n  
nStartPos = new long[bean.getNSplitter()]; [zJ|61^  
nEndPos = new long[bean.getNSplitter()]; tqD=)0Uzs  
} ls({{34NF  
slnvrel  
(&i c3/-  
]WYddiF  
} vJj}$AlI  
Yr)<1.K4,M  
#J'V,_ wH  
public void run() 7TtDI=f  
{ B4/\=MXb  
//获得文件长度 ()^tw5e'^  
//分割文件 +aQM %~  
//实例FileSplitterFetch ~F " w  
//启动FileSplitterFetch线程 kD46Le++B  
//等待子线程返回 719lfI&s  
try{ S'(IG m4  
if(bFirst) {ui{Yc  
{ bn:74,GeyK  
nFileLength = getFileSize(); U<|*V5   
if(nFileLength == -1) mrQT:B\8  
{ ~K@p`CRbV  
System.err.println("File Length is not known!"); H0\' ,X  
} @$fvhEkrT@  
else if(nFileLength == -2) RF}R~m9]  
{ <:>[24LJ{  
System.err.println("File is not access!"); "_0sW3rG  
} NT=)</v  
else )8E[xBaO  
{ 8;d./!|'&g  
for(int i=0;i<nStartPos.length;i++) bjBXs;zr@\  
{ ThY\K>@]  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); T@xaa\bzg  
} V'FKgzd  
for(int i=0;i<nEndPos.length-1;i++) #Xk/<It  
{ 8I~*9MUp  
nEndPos = nStartPos[i+1]; {nMCU{*k  
} soOfk!b  
nEndPos[nEndPos.length-1] = nFileLength; 4axuE]  
} t>vr3)W  
} G0u H6x?  
*|OUd7P:hU  
m KJO?7tj  
//启动子线程 QL\3|'a  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^|%N _ s  
for(int i=0;i<nStartPos.length;i++) XMF#l]P  
{ W0S\g#  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [:/mjO K  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ky{@*fg.  
nStartPos,nEndPos,i); =d$m@rc0r  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +^q- v-  
fileSplitterFetch.start(); ^7Ebg5<  
} ZEB,Q~  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &8dj*!4H  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 62o nMY  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J u"/#@  
nEndPos = " + nFileLength); [U,hb1Wi3  
// fileSplitterFetch[nPos.length-1].start(); s( :N>K5*  
(g>&ov(d  
* $|9e  
//等待子线程结束 a|ZJzuqo  
//int count = 0; v2ab84 C*  
//是否结束while循环 L*6>S_l[  
boolean breakWhile = false; lvG+9e3+  
8w ]'U  
#[]B: n6  
while(!bStop) ]4Q~x  
{ 6RfS_  
write_nPos(); MFz6y":~  
Utility.sleep(500);  Cy5M0{  
breakWhile = true; *iUR1V Y  
;y;UgwAM  
7WHq'R{@  
for(int i=0;i<nStartPos.length;i++) !]MGIh#u  
{ L4<=,}KS  
if(!fileSplitterFetch.bDownOver) ~PX#' Jr  
{ au+ a7~0~  
breakWhile = false; ,IPryI   
break; /BrbP7  
} ;It1i`!R  
} ahR-^^'$  
if(breakWhile) p[%B#(]9,  
break; ?:7.3{|Aq  
vv D515i  
Q SvgbjdE  
//count++; nc?Oj B  
//if(count>4) W . dm1  
// siteStop(); >Ft:&N9L{  
} BAy)P1  
>L^ 2Z*  
-l <[CI  
System.err.println("文件下载结束!"); FXbalQ?^  
} QaLVIsnfN  
catch(Exception e){e.printStackTrace ();} DuRC1@e  
} +L pMNnl6  
9-.`~v  
5r^u7k  
//获得文件长度 2SYV2  
public long getFileSize() nC\LDeKc  
{ N#^o,/  
int nFileLength = -1; 1ifPc5j}  
try{ ?dvcmXR  
URL url = new URL(siteInfoBean.getSSiteURL()); S^)xioKsJ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \; zix(N[5  
httpConnection.setRequestProperty("User-Agent","NetFox"); `llSHsIkXb  
N lB%Qu  
b|U3\Fmc  
int responseCode=httpConnection.getResponseCode(); b(_PV#@$  
if(responseCode>=400) 5xc-MkIRL  
{ `IK3e9QpcA  
processErrorCode(responseCode); R-5e9vyS  
return -2; //-2 represent access is error /&RS+By(i  
} XtIY8wsP  
^oZD44$  
KCfcEz  
String sHeader; E>rWm_G  
gX]'RBTb  
Lu~M=Fh  
for(int i=1;;i++) T0BM:ofx  
{ W4=<hB  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h|.*V$3  
//Utility.log(in.readLine()); =mh)b]].4\  
sHeader=httpConnection.getHeaderFieldKey(i); 6}q# c  
if(sHeader!=null) tSq`_[@  
{ I< Rai"  
if(sHeader.equals("Content-Length")) bdr !|WZ  
{ rY(^6[!  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \E,Fe:/g  
break; yQ+C}8r5  
} lR3JyYY{X  
} J,^eq@(  
else vU, ]UJ}  
break; } mEsb?  
} x2z%J,z@4  
} >=ng?  
catch(IOException e){e.printStackTrace ();} g/x\#W  
catch(Exception e){e.printStackTrace ();} G 4 C 7  
i)+2? <]  
+FYhDB~m  
Utility.log(nFileLength); QfsTUAfR  
e[J0+ x#;r  
8}Su7v1  
return nFileLength; }P"JP[#E\  
} df!n.&\y!  
X" ;ly0Mb  
Qrt> vOUE7  
//保存下载信息(文件指针位置) wvNddu>@  
private void write_nPos() ceGo:Aa<)  
{  JS!  
try{ I)F3sS45}  
output = new DataOutputStream(new FileOutputStream(tmpFile)); #zc{N"!  
output.writeInt(nStartPos.length); j?P8&Fm<  
for(int i=0;i<nStartPos.length;i++) D[R<H((  
{ xnG,1doa  
// output.writeLong(nPos); 3}X;WE `  
output.writeLong(fileSplitterFetch.nStartPos); |%-:qk4rG  
output.writeLong(fileSplitterFetch.nEndPos); oj~0zJI  
} Y7 `i~K;  
output.close(); 9oJ=:E~CP  
} [)83X\CO  
catch(IOException e){e.printStackTrace ();} e025m}%SU  
catch(Exception e){e.printStackTrace ();} Gv zw=~8  
} '}T6e1#JV  
=H2.1 :'  
EcW$'>^  
//读取保存的下载信息(文件指针位置) cakb.Q  
private void read_nPos() ,-{ 2ai_  
{ $@:z4S(  
try{ 7nL3+Pq  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b<mxf\b  
int nCount = input.readInt(); /=2  
nStartPos = new long[nCount]; Qd$!?h  
nEndPos = new long[nCount]; j{u! /FD  
for(int i=0;i<nStartPos.length;i++) 1?bX$$y l;  
{  *$o{+YP  
nStartPos = input.readLong(); xYCX}bksh  
nEndPos = input.readLong(); N HL{.8L{  
} ['rqz1DL5  
input.close(); y #Xq@  
} |lhVk\X  
catch(IOException e){e.printStackTrace ();} GS4 HYF  
catch(Exception e){e.printStackTrace ();} ce\ F~8y  
} \Q<Ur&J]%  
0 SeDBs  
G6L /Ny3>_  
private void processErrorCode(int nErrorCode) |KxFi H  
{ %8lF%uu!x  
System.err.println("Error Code : " + nErrorCode); K@z zseQ}=  
} pC'GKk 8  
=D2x@ank[  
< l%3P6|  
//停止文件下载 x0!5z1KQh  
public void siteStop() ;Y>cegG\  
{ RZeU{u<O  
bStop = true; #]!0$z|Z  
for(int i=0;i<nStartPos.length;i++)  uM9[  
fileSplitterFetch.splitterStop(); '9MtIcNb  
,pz^8NJAI  
<H)I06];  
} x\Det$3Kx  
} r{gJ[%  
//负责部分文件的抓取 4(f4 4' ^  
**FileSplitterFetch.java |Skk1 #  
*/ 5B'};AQ  
package NetFox; Zom7yI  
O8N\  
Xbb('MoI63  
import java.io.*; 1>SCY _C v  
import java.net.*; ~"+Fp&[9f  
9\]%N;;Lo  
-  zQ  
public class FileSplitterFetch extends Thread { t<6`?\Gk  
{IW pI *  
nsJN)Pt  
String sURL; //File URL '_~=C-g  
long nStartPos; //File Snippet Start Position Ex ?)FL$4  
long nEndPos; //File Snippet End Position `_6!nk q8  
int nThreadID; //Thread's ID jtk2>Ol   
boolean bDownOver = false; //Downing is over @,63%  
boolean bStop = false; //Stop identical b1}P3W  
FileAccessI fileAccessI = null; //File Access interface 4#z@B1Jx  
,afh]#  
Dm1;mRS+  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^< ,Np+  
{ Jk)^6  
this.sURL = sURL; 0vs9# <&V  
this.nStartPos = nStart; q=5#t~?  
this.nEndPos = nEnd; +FWkhmTv  
nThreadID = id; Gv!* Qk4  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~$N%UQn?b#  
} ~5HI9A4^  
}7Si2S  
1X4v:rI  
public void run() #qk A*WP  
{ #`C ;@#xr  
while(nStartPos < nEndPos && !bStop) | 1Fy  
{ PEPBnBA&1  
mlR*S<Z  
!TRJsL8  
try{ a r#p7N  
URL url = new URL(sURL); eyZ /%4'q  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7mSVL\\^  
httpConnection.setRequestProperty("User-Agent","NetFox"); E lt=/,v`!  
String sProperty = "bytes="+nStartPos+"-"; JBCcR,\kM*  
httpConnection.setRequestProperty("RANGE",sProperty); .VVY]>bJg@  
Utility.log(sProperty); RpE69:~PV  
Y" s1z<?  
Dq!Vo;s2  
InputStream input = httpConnection.getInputStream(); -i@1sNx&'  
//logResponseHead(httpConnection); 0)V<)"i  
`?Yh`P0  
ldo7}<s  
byte[] b = new byte[1024]; iNR6BP W  
int nRead; 5uK:f\y)l  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vMXS%Q  
{ %v\0Dm+A  
nStartPos += fileAccessI.write(b,0,nRead); ;%Jw9G\h  
//if(nThreadID == 1) |\ j'Z0  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j(!M  
} 2B7X~t>8a  
xn&G`  
<@}~Fp@  
Utility.log("Thread " + nThreadID + " is over!"); *]fBd<(8  
bDownOver = true; d*=P8QwL|  
//nPos = fileAccessI.write (b,0,nRead); /lSz8h2  
} -y{o@  
catch(Exception e){e.printStackTrace ();} s% "MaDz  
} /a%5!)NE%  
} &,xN$  
h#?L6<*tm  
Us'm9 J  
//打印回应的头信息 rS>JzbWa  
public void logResponseHead(HttpURLConnection con) Z;bzp3v  
{ =N`"%T@=  
for(int i=1;;i++) c~(+#a  
{ N %-Cp)  
String header=con.getHeaderFieldKey(i); r>S?,qr  
if(header!=null) K vC`6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A('=P}I^  
Utility.log(header+" : "+con.getHeaderField(header)); *M5 =PQfb  
else Y&aFAjj  
break; |b{XnD_g  
} Au$|@  
} Ql> DS~a  
bR@ e6.<i  
.Y!*6I  
public void splitterStop() g]R }w@nJ  
{ M-u:8dPu  
bStop = true; o+SD(KVn-  
} SIjdwr!+ZZ  
5C/W_H+9iK  
Lc6Wj'G G  
} xR2E? 0T  
a&~d,vC  
T9\wkb.  
/* \X5{>nNh  
**FileAccess.java bort2k  
*//文件访问(定位,写) jQzq(oDQw  
package NetFox; rl9YB %P  
import java.io.*; DPJ#Y -0  
M"2Tuwz  
5bX SN$7|  
public class FileAccessI implements Serializable{ }s=D,_}m  
bE.,)GY  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 NyI0 []z  
RandomAccessFile oSavedFile; j`A%(()d  
long nPos; }3F8[Td.~N  
FyX\S=  
m(E-?VMHo  
public FileAccessI() throws IOException f( 5c  
{ 1HG~}E  
this("",0); v!T%xUb0  
} D(D:/L8T,  
CN@bJo2  
wQ qI@  
public FileAccessI(String sName,long nPos) throws IOException Y  9]  
{ ~U#afGH$  
oSavedFile = new RandomAccessFile(sName,"rw"); ~h 6aw  
this.nPos = nPos; ,F(nkbt  
oSavedFile.seek(nPos); mL`,v WL/`  
} |GtTz&  
@FKNB.>  
f8kPbpV,  
public synchronized int write(byte[] b,int nStart,int nLen) .{x-A{l  
{ 9l9 nT  
int n = -1; uPc}a3'?  
try{ -! Hn,93  
oSavedFile.write(b,nStart,nLen); L6Ykv/V  
n = nLen; NS @j`6/U  
} -;cZW.<  
catch(IOException e) C1^=se  
{ 7A?~a_Ep  
e.printStackTrace (); Enn7p9&  
} IlJ6&9  
.}S9C]d:a  
okJ+Yl.[?7  
return n; 5*u0VabC<  
} +uKh]RP  
vO!p8r F  
PXG)?`^NX  
} S\K;h/;V  
^%V'l-}/  
lN#W  
/* v{ Md4 p  
**SiteInfoBean.java Tz3 L#0:j  
*/ 9 o6ig>C  
package NetFox; 9F)+p7VJq  
n#Xi Co_\  
"hi?/B#d  
public class SiteInfoBean { DZ -5A  
HtB>#`'  
0]=|3-n  
private String sSiteURL; //Site's URL  -iWt~  
private String sFilePath; //Saved File's Path z^+f3-Z  
private String sFileName; //Saved File's Name j'FSd*5m  
private int nSplitter; //Count of Splited Downloading File ;rYL\`6L  
1=gE ,k5H  
<7R\ #  
public SiteInfoBean() A ><  
{//nSplitter的缺省值为5 3maiBAOKz  
//default value of nSplitter is 5 UXwnE@`F  
this("","","",5); mH2XwA|  
} Tt #4dm-  
0>Iy`>]  
G vMhgG=D  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F7lhLly  
{ SYd4 3P A  
sSiteURL= sURL; ;rZR9fR  
sFilePath = sPath; lJ;7sgQ#  
sFileName = sName; P*Va<'{:{  
this.nSplitter = nSpiltter; Lg Xc}3  
TeaP\a  
Q.X)QCp#r  
} z ^t6VFM  
T#kPn#|  
0w9)#e+JS  
public String getSSiteURL() TELN4*  
{ <5(P4cm9  
return sSiteURL; _0dm?=  
} &SuWmtq  
_Y@vO  
W5 ^eCYHoi  
public void setSSiteURL(String value) r:0F("},  
{ z5`AJrj%  
sSiteURL = value; *Z'*^Y1le  
} V .+ mK|)  
Vc0C@*fVM  
lWr=79  
public String getSFilePath() ln.'}P  
{ {7swE(N  
return sFilePath; XE8>& & X  
} T1AD(r\W5  
hB/4.K]8  
a!rU+hiC  
public void setSFilePath(String value) __N< B5E  
{ VbX+`CwH  
sFilePath = value; Ahl-EVIr<  
} 4.Luy  
B8A-|S!,U  
hZ@frbuowk  
public String getSFileName() Z./$}tVUG  
{ Kv(2x3("  
return sFileName; E;m]RtvH  
} VRden>vKN  
CqK&J /8  
Kz>bfq7  
public void setSFileName(String value) iY@wg 8ry  
{ S&(MR%".  
sFileName = value; $>^DkrOd  
} ZYRZ$87jZ  
e=uElp'%  
C:z+8wt  
public int getNSplitter() LB9D6,*t  
{ khFr%u ?S  
return nSplitter; zv[$ N,  
} y2Eq-Ie  
96G8B62  
n}0n!Pr^  
public void setNSplitter(int nCount) \tR](, /  
{ V+`gkWe/  
nSplitter = nCount; y,&'nk}  
} 0xE37Ld,  
} 2IMU &  
3 s%Kw,z  
h&5bMW  
/* GZ=7)eJ~<  
**Utility.java mQL8ec_c  
*/ WXq=FZ-  
package NetFox; FTu6%~M/  
%vF,wQC  
l-^2>K[  
public class Utility { s"OP[YEke/  
9mA6nmp  
HrOq>CSR  
public Utility() i28WgDG)5  
{ A]<+Aq@{  
)ZZjuFQJ)  
wPr9N}rf  
} Ygeg[S!7  
8M6 Xd]{%  
//线程睡眠 M~/Pk7CC  
public static void sleep(int nSecond) b"4'*<=au  
{ '%Fg+cZN\  
try{ -9PJ4"H  
Thread.sleep(nSecond); K Eda6zZH  
} I:|<};m m  
catch(Exception e) Fw{:fFZC[  
{ %<dvdIB  
e.printStackTrace (); WZ@hP'Zc  
} I1f4u6\*X  
} }xx"  
,5*Z<[*  
//日志 ) wZ;}O  
public static void log(String sMsg) L<D<3g|4  
{ 8NF93tqD6  
System.err.println(sMsg); 7C;oMh5  
} @ra^0  
1>yh`Bp\=  
zG\& ZU  
public static void log(int sMsg) bwR$9 10b  
{ kh4., \'  
System.err.println(sMsg); 8n&Gn%DvX  
} !l6Ez_'  
} P^3`znq{  
$Wy(Wtrx|  
%3%bRP  
/* o:wI{?%-3  
**TestMethod.java [,bra8f[C  
*/ ;OMR5KAz  
package NetFox; N4HIQ\p  
6y+_x'  
hr@kU x  
public class TestMethod { $.+_f,tU  
kuq&8f~!  
2`'g 9R  
public TestMethod() ~:JoKm`vU  
{ ///xx/weblogic60b2_win.exe aRV .;S  
try{ WWEZTFL:j  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #"qP4S2  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Cg8s9qE?  
SiteFileFetch fileFetch = new SiteFileFetch(bean); +,Ud 3iS  
fileFetch.start(); PtTL tiE~  
} ikd1KF+I  
catch(Exception e){e.printStackTrace ();} WqO4_;X6/  
jd.{J{o  
PQd*)6K:A  
} u~xfI[8C  
p3,m),  
JW},7Ox  
public static void main(String[] args) ?S<`*O +  
{ MvKr~  
new TestMethod(); =vs]Kmm  
} /2f  
} %f?Z/Wn  
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