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http断点续传简单实现(java)

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/* EjR_-8@FK  
**SiteFileFetch.java GJ1;\:cQq  
*/ ~K~b`|1  
package NetFox; qIbg 4uE  
import java.io.*; rU=b?D)n!w  
import java.net.*; (C`FicY  
O{k89{  
[=F>#8=  
public class SiteFileFetch extends Thread { W.,% 0cZ  
R^J.?>0  
t&GA6ML#s  
SiteInfoBean siteInfoBean = null; //文件信息Bean 9VoDhsKk  
long[] nStartPos; //开始位置 YgE]d?_h  
long[] nEndPos; //结束位置 4M @ oj  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ]d@^i)2LF  
long nFileLength; //文件长度 4F05(R8k  
boolean bFirst = true; //是否第一次取文件 mje<d"bW  
boolean bStop = false; //停止标志 jM5_8nS&d  
File tmpFile; //文件下载的临时信息 =\~E n5  
DataOutputStream output; //输出到文件的输出流 r0\cc6  
?EI'^xg  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) op hH9D  
public SiteFileFetch(SiteInfoBean bean) throws IOException de> ?*%<  
{ =X-^YG3x  
siteInfoBean = bean; P?9nTG  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); u0m5JD0/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); $%7I:  
if(tmpFile.exists ()) 8tb6 gZz  
{ M{`/f@z(  
bFirst = false; :s'o~   
read_nPos(); -O|&c9W.O  
} -DTB6}kw  
else r<;l{7lY_  
{ k? 3S  
nStartPos = new long[bean.getNSplitter()]; ;i<$7MR.e  
nEndPos = new long[bean.getNSplitter()]; ic%?uWN  
} .6>  hD1'  
i 8l./Yt/  
XB0a dp  
&|v{#,ymeb  
} PX;Vo~6  
3/X-Cr+d  
5Z/yhF.{  
public void run() 5]jx5!N  
{ CzYGq  
//获得文件长度 >(hSW~i~  
//分割文件 N>+P WE$  
//实例FileSplitterFetch S8 :"<B)  
//启动FileSplitterFetch线程 &J8 Z@^  
//等待子线程返回 hf;S]8|F  
try{ Q*]$)D3n  
if(bFirst) QL2Nz@|k  
{  )|v^9  
nFileLength = getFileSize(); 8RVS)D''  
if(nFileLength == -1) "mP&8y 9F  
{ h}<0/  
System.err.println("File Length is not known!"); Aj [?aL  
} sU\c#|BSC"  
else if(nFileLength == -2) x&'o ]Y  
{ M'kVL0p?vN  
System.err.println("File is not access!"); rkkU"l$v  
} led))qd@V-  
else z"tjDP  
{ 6yY.!HRkr  
for(int i=0;i<nStartPos.length;i++) ~@{w\%(AK]  
{ >DHp*$y  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); dXmV@ Noo  
} ))!Bg?t-  
for(int i=0;i<nEndPos.length-1;i++) #Mh{<gk%ax  
{ X*i/A<Y`=  
nEndPos = nStartPos[i+1]; / /'Tck  
} :z]}ZZ  
nEndPos[nEndPos.length-1] = nFileLength; {jjSJIV1  
} MhNFW'_  
} j`O7=-  
OB(pIzSe  
h;-a`@rO ;  
//启动子线程 ;x-(kIiE  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #?dUv#  
for(int i=0;i<nStartPos.length;i++) z"lqrSJ:  
{ /RGNAHtIi  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @}WNKS&m  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), blGf!4H  
nStartPos,nEndPos,i); *I0Tbc O  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J1bA2+5.*e  
fileSplitterFetch.start(); $(ewk):  
} ^(ScgoXva  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;6ky5}z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ({4]  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ",  9:5:`' b  
nEndPos = " + nFileLength); " Ya9~6  
// fileSplitterFetch[nPos.length-1].start(); 'Gjq/L/x  
&rp!%]+xAM  
RPVT*`o  
//等待子线程结束 P"1 S$oc  
//int count = 0; [8"ojhdV  
//是否结束while循环 #Z\ O}<  
boolean breakWhile = false; Cp#)wxi6[y  
A3HF,EG  
{XgnZ`*  
while(!bStop) 5o#Yt  
{ ,_D" ?o  
write_nPos(); h>alGLN>  
Utility.sleep(500); 1G;8MPU  
breakWhile = true; JWROYED  
XF|WCZUnY%  
9XX>A*  
for(int i=0;i<nStartPos.length;i++) K^zDNIQU  
{ 6"U8V ?E  
if(!fileSplitterFetch.bDownOver) -I":Z2.fR  
{ C9qJP^F  
breakWhile = false; 3NIUW!gr  
break; |ETiLR=&  
} ][d,l\gu+s  
} y:d{jG^  
if(breakWhile) ;gMgj$mI  
break; F[saP0 *  
n,j$D62[  
[iS,#w` 5  
//count++; M\oTZ@  
//if(count>4) Sw8kIC  
// siteStop(); WA$ JI@g  
} ^N{ltgQY  
u=r`t(Z1H  
N8v'70  
System.err.println("文件下载结束!"); -kpswP  
} ""{|3XJe  
catch(Exception e){e.printStackTrace ();} Wkzs<y"  
} BI2; ex  
+Llo81j&  
0:&ZnE}##  
//获得文件长度 ~GJN@ka4%  
public long getFileSize() 15{Y9!  
{ GKiukX$'  
int nFileLength = -1; v>A=2i*j  
try{ Q7gY3flg  
URL url = new URL(siteInfoBean.getSSiteURL()); ,e`'4H  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ifK%6o6  
httpConnection.setRequestProperty("User-Agent","NetFox"); ~]'pY  
e-5?p~>  
 npp[@*~  
int responseCode=httpConnection.getResponseCode(); ^j)BKD-  
if(responseCode>=400) K93p"nHN  
{ ]"~51HQZ  
processErrorCode(responseCode); X"q!Y#)  
return -2; //-2 represent access is error k~3.MU  
} bU54-3Ox*  
hWo=;#B*  
]3Dl)[R  
String sHeader; ,xI%A, (,;  
'b/ <x|  
x;\wY'  
for(int i=1;;i++) 28andfl  
{ gNpJ24QK  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;WU<CKYG*  
//Utility.log(in.readLine()); >dzsQ^Nj  
sHeader=httpConnection.getHeaderFieldKey(i); E7zm{BX]  
if(sHeader!=null) Bi3+)k>u7  
{ ,#]t$mzbQ(  
if(sHeader.equals("Content-Length")) x3p ND  
{ aqU' T  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i/So6jW  
break; ]@^coj[  
} Xz 4 x  
} Yw; D:Y(  
else 5 BtX63  
break; _-~`03 `!  
} Zm ogM7B  
} sJ z@7.  
catch(IOException e){e.printStackTrace ();} wJ<Oo@snm  
catch(Exception e){e.printStackTrace ();} h*B|fy4K9U  
!ZRs;UZ>o  
o>/O++7Ra  
Utility.log(nFileLength); c`*TPqw(B[  
,m=4@ofX  
-fI@])$9J  
return nFileLength; *Vw\'%p*  
} 8qEK+yi,  
Rli:x  
A@*:<Hs%  
//保存下载信息(文件指针位置) efP&xk  
private void write_nPos() '3IC*o"  
{ x35cW7R}T_  
try{ LPYbHo3fq  
output = new DataOutputStream(new FileOutputStream(tmpFile)); E\nv~Y?SG  
output.writeInt(nStartPos.length); X>YsQrK(ig  
for(int i=0;i<nStartPos.length;i++) 0c^>eq]  
{ X[gn+6WB%  
// output.writeLong(nPos); L6Wt3U`l  
output.writeLong(fileSplitterFetch.nStartPos); dsx]/49<  
output.writeLong(fileSplitterFetch.nEndPos); BvrB:%_:  
} fF vF\  
output.close(); Zk8|K'oHx  
} 6]zd.W  
catch(IOException e){e.printStackTrace ();} =qy=-j]  
catch(Exception e){e.printStackTrace ();} 4_v]O  
} {O<l[|Ip  
C:8_m1Y{  
:,b iyJt  
//读取保存的下载信息(文件指针位置) {gNV[45  
private void read_nPos() r|e-<t4.9L  
{ D]a<4a 18  
try{ !\8  ;d8  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); VQ5nq'{v  
int nCount = input.readInt(); D?yG+%&9  
nStartPos = new long[nCount]; |t iUej  
nEndPos = new long[nCount]; %1 vsN-O}8  
for(int i=0;i<nStartPos.length;i++) C;QAT  
{ jn >d*9u  
nStartPos = input.readLong(); ^.k |SK`U  
nEndPos = input.readLong(); BBG3OAyg_  
} #GDe0 8rOw  
input.close(); ,#d? _?/:O  
} ~=<}\a~  
catch(IOException e){e.printStackTrace ();} rNjn~c  
catch(Exception e){e.printStackTrace ();} ZQ^r`W9_ +  
} C98]9  
(/-hu[:  
3kcTE&1^  
private void processErrorCode(int nErrorCode) :c9U>1`g&  
{ 6 5y+Z  
System.err.println("Error Code : " + nErrorCode); Y{v(p7pl  
} Hn>B!Bm*  
lv vs%@b>  
;,i]w"*  
//停止文件下载 i wxVl)QL  
public void siteStop() )[mwP.T=  
{ 5zFR7/p{  
bStop = true; \I"Z2N>^z  
for(int i=0;i<nStartPos.length;i++) ]?x: Qm'yo  
fileSplitterFetch.splitterStop(); <<=WY_m}  
#P]#9Ty:  
D`J6h,=2l/  
} J_Ltuso  
} #ET/ =  
//负责部分文件的抓取 LK6; ? m  
**FileSplitterFetch.java A;\ 7|'4  
*/ Q#h 9n]5  
package NetFox; &B! o,qp  
+w@M~?>  
~%?`P/.o  
import java.io.*; C2Xd?d  
import java.net.*; jM-)BP6f4  
1]IQg;q  
l]~n3IK"  
public class FileSplitterFetch extends Thread { "S 3wk=?4  
V[-jD8=' 3  
lEHzyh}2k  
String sURL; //File URL :l|%17N  
long nStartPos; //File Snippet Start Position HV6f@  
long nEndPos; //File Snippet End Position *(PL _/:  
int nThreadID; //Thread's ID &Ysosy*  
boolean bDownOver = false; //Downing is over |6=p{ y  
boolean bStop = false; //Stop identical z'uK3ng\hH  
FileAccessI fileAccessI = null; //File Access interface HB Iip?  
l;y7]DO  
>.dWjb6t  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vSi_t K4  
{ '* \|; l#1  
this.sURL = sURL; zC _<(4$-"  
this.nStartPos = nStart; TuW%zF/  
this.nEndPos = nEnd; F(na{<g};  
nThreadID = id; h?bb/T+'  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p-1 3H0Kt  
} o9cM{ya/>  
5M9 I,  
&WNf M+  
public void run() JaB<EL-9r2  
{ ~T) Q$  
while(nStartPos < nEndPos && !bStop) u,}{I}x_  
{ U|g:`v7  
4 C}bJzZ  
Sz H"  
try{ &\apwD  
URL url = new URL(sURL); /-bO!RTwf  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aW!@f[%~F  
httpConnection.setRequestProperty("User-Agent","NetFox"); A:7k+4  
String sProperty = "bytes="+nStartPos+"-"; dt2$`X18  
httpConnection.setRequestProperty("RANGE",sProperty); (@iMLuewK  
Utility.log(sProperty); 5/po2V9)  
WVY\&|)$  
]E]2o  
InputStream input = httpConnection.getInputStream(); ]p_@@QTC  
//logResponseHead(httpConnection); 5jUYN-$GO  
i1S>yV^l  
+3KEzo1=)  
byte[] b = new byte[1024]; :1Q!$  m  
int nRead; ChCrL [2  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) keB&Bjd&  
{ UQB "v3Z  
nStartPos += fileAccessI.write(b,0,nRead); SM`w;?L:?  
//if(nThreadID == 1) +-E~6^>  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1Bpv"67  
} <{~6}6o  
LBF 1;zjK  
_E@ :O+K  
Utility.log("Thread " + nThreadID + " is over!"); gn3jy^5  
bDownOver = true; Nbp!teH6  
//nPos = fileAccessI.write (b,0,nRead); SR DXfkoI  
} eds26(  
catch(Exception e){e.printStackTrace ();} #> j.$2G>  
} |j 6OM{@  
} ,=l7:n  
tU_y6  
2(/g}  
//打印回应的头信息 i+gQE!  
public void logResponseHead(HttpURLConnection con) 3E 3HL7  
{ /="~gq@  
for(int i=1;;i++) K~22\G`  
{ 6 ND`l5  
String header=con.getHeaderFieldKey(i); ei rzYt  
if(header!=null) n> ^[T[.S  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <Qxh)@ N  
Utility.log(header+" : "+con.getHeaderField(header)); H@ t'~ZO  
else o1<_fI  
break; hGiz)v~  
} gdkwWoN .  
} f%V4pzOc"  
}!6\|;Qsz,  
?wO-cnl  
public void splitterStop() y.[Mnj  
{ 'Y]mOD^ p  
bStop = true; NMA}Q$o s  
} ,Jd ',>3  
W^s ;Bi+Nw  
)n,P"0  
} zA[0mkC?$  
%rxO_  
J_FNAdQt  
/* g&`pgmUX  
**FileAccess.java fJ ,1Ef;Z  
*//文件访问(定位,写) +Z85HY{  
package NetFox; Ek6MYc8<b~  
import java.io.*; 9]e V?yoA8  
bR V+>;L0@  
;X?mmv'  
public class FileAccessI implements Serializable{ .-<k>9S7_  
IKi5 v~bE  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B9wPU1  
RandomAccessFile oSavedFile; w+N> h;j  
long nPos; aXL{TD:]  
{RF-sqce  
&B|D;|7H  
public FileAccessI() throws IOException zD<or&6  
{ og0*Nt+  
this("",0); *W kIq>  
} f"St&q>[s  
O)"gS!,  
aJcf`<p   
public FileAccessI(String sName,long nPos) throws IOException 95z]9UL  
{ ca>Z7qT!  
oSavedFile = new RandomAccessFile(sName,"rw"); 0X^Ke(/89  
this.nPos = nPos; ;g~TWy^o  
oSavedFile.seek(nPos); /r=tI)'$  
} ~ {Mn{  
I}t#%/'YA  
k68F-e[i^  
public synchronized int write(byte[] b,int nStart,int nLen) .B\5OI,]  
{ "U\4:k`:  
int n = -1; kS!viJwtT  
try{ ,dx3zBI  
oSavedFile.write(b,nStart,nLen); A]DTUdL  
n = nLen; G8;w{-{m  
} fXcm|U,ho  
catch(IOException e) =" g*\s?r  
{ $ >EYhLBa  
e.printStackTrace (); phgm0D7  
} a AB`G3  
=Jym%m  
q#8 [  
return n; f{FDuIl n  
} =XY\iV1J*  
qBCK40   
Dre]AsgiV  
} YiPoYlD*n<  
rp0ZvEX  
d`F&aC  
/* U\R}`l  
**SiteInfoBean.java Rb{U+/gq  
*/ X#e1KZ  
package NetFox; MzL1Bh!M  
Cm\6tD  
'CN|'W)g7  
public class SiteInfoBean { *;fw%PW  
=|YxDas  
;]pJj6J&v  
private String sSiteURL; //Site's URL D`VM6/iQR  
private String sFilePath; //Saved File's Path ph-ATJ"  
private String sFileName; //Saved File's Name X0n~-m"m  
private int nSplitter; //Count of Splited Downloading File QI3Nc8t_2  
9J?wO9rI  
iURk=*Z=  
public SiteInfoBean() E~_]Lfs)  
{//nSplitter的缺省值为5 E8~}PQW:I  
//default value of nSplitter is 5 :Cp'm'omb  
this("","","",5); /=gOa\k|p  
} 2^l[(N  
=hMY2D  
ruazOmnn~  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [!U?}1YQ  
{ !H}vu]R  
sSiteURL= sURL; iV eC=^1  
sFilePath = sPath; .3MIcj=p  
sFileName = sName; /\W Qx e  
this.nSplitter = nSpiltter; <0PT"ij  
,.qMEMm  
r9ww.PpNk#  
} "1HRLci  
k+DR]icv  
'FS?a  
public String getSSiteURL() gR}35:$Z-  
{ 1)[]x9]^q'  
return sSiteURL; G3{=@Z1  
} &T}''  
y})70w@ +_  
g=$1cC+(  
public void setSSiteURL(String value) >G~R,{6U  
{ >z.<u|r2  
sSiteURL = value; ?|ZTaX6A  
} ti<;7Yb  
f0BdXsV#g  
b/Xbs0q  
public String getSFilePath() ME=/|.}D<  
{ Rh>}rGvCUN  
return sFilePath; *>+,(1Fz  
} Uv4`6>Ix  
R?p00  
X 51Yfr  
public void setSFilePath(String value) T0]*{k(FR  
{ ]7/ b/J  
sFilePath = value; eVM/uDD  
} dF~8XYo  
>~Qr  
/mK?E5H'r1  
public String getSFileName() _Y[jyD1>  
{ 56Vb+0J'  
return sFileName; gL3"Gg3  
} D2,z)O%VK  
wWp(yvz  
/-i !;!  
public void setSFileName(String value) 6HlePTf8  
{ ,yTjU{<"  
sFileName = value; <fs2fTUeqF  
} s\P2Bp_{  
?Oc{bF7  
Ck /F9(  
public int getNSplitter() 2~t[RY  
{  ]$,UPR/3  
return nSplitter; >N.]|\V  
} -@Uqz781  
q/4 [3h  
E~ a3r]V/  
public void setNSplitter(int nCount) YLVPAODY  
{ 51QRM32Y  
nSplitter = nCount; A|@_}h"WG  
} d` [HT``  
} E~AjK'Z  
;-Jb1"5  
+L5\;  
/* "XT"|KF|D  
**Utility.java STJJU]H  
*/ - > J_ ~  
package NetFox; C*G=cs\i  
p^pOuy8  
IO/4.m-aN#  
public class Utility { 41_SRh7N  
.n=Z:*JqQ  
s-S }i{Z!  
public Utility() SM^-Z|d?  
{ ai0Ut   
+nT'I!//  
R9! Uo  
} TET`b7G  
1=]kWp`i  
//线程睡眠 !L95^g   
public static void sleep(int nSecond) jU5}\oP@  
{ 7^Yk`Z?|a  
try{ wm+})SOX9  
Thread.sleep(nSecond); Rtjqx6-B;  
} /By)"  
catch(Exception e) mB0l "# F  
{ 1U,1)<z~u  
e.printStackTrace (); QL$S4 J"  
} %xQ.7~  
} .WQ+AE8Q  
oQL59XOT4  
//日志 8+Td-\IMk  
public static void log(String sMsg) {vE(l'  
{ aceZ3U>W  
System.err.println(sMsg); e hA;i.n  
} 42\-~]  
Nlj^D m  
q SejLh6  
public static void log(int sMsg) /N-_FMl?  
{ ,Hgc-7g@Y  
System.err.println(sMsg); W k}AmC  
} X.TI>90{  
} nJbbzQ,e  
(S^8UV  
Ou>vX[{  
/* )}L??|#  
**TestMethod.java BJS-Jy$-  
*/ ~j'l.gQb  
package NetFox; "p3_y`h6+  
9TAj) {U%'  
SI6B#u-i  
public class TestMethod { [>|FB'  
>\!4Mk8  
Bu]t*$  
public TestMethod() LA[g(i 7  
{ ///xx/weblogic60b2_win.exe jp+_@S>  
try{ Pe2wsR"_U  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -TV?E%r  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %AW4.3()8  
SiteFileFetch fileFetch = new SiteFileFetch(bean); n$:IVX"2b  
fileFetch.start(); "+uNmUUnm  
} Ap$y%6  
catch(Exception e){e.printStackTrace ();} > MG>=A  
UgN28YrW  
-!({B H-M_  
} pDh se2  
\sA*V%n  
Yh)Isg|0>  
public static void main(String[] args) :L 3&FA   
{ sFDG)  
new TestMethod(); W~Z<1[  
} a83g\c5   
} <*EZ@XoN>  
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