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http断点续传简单实现(java)

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/* |V|+lx'sc  
**SiteFileFetch.java 0.Vi9 7`  
*/ ] fwZAU  
package NetFox; {( tHk_q  
import java.io.*; Ri)uq\E/#  
import java.net.*; 9Ah[rK*}  
8-M e.2K  
jfp z`zE  
public class SiteFileFetch extends Thread { qP1FJ89H  
Vn|1v4U!  
~h)&&' a  
SiteInfoBean siteInfoBean = null; //文件信息Bean Vrkf(E3_V  
long[] nStartPos; //开始位置 , ZFE(  
long[] nEndPos; //结束位置 (= ;N{u  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 R_N:#K.M  
long nFileLength; //文件长度 Y; ) .+si  
boolean bFirst = true; //是否第一次取文件 }6]0hWsN[  
boolean bStop = false; //停止标志 73F5d/n  
File tmpFile; //文件下载的临时信息 Y)|N"f;  
DataOutputStream output; //输出到文件的输出流 .`p&ATg v  
{5j66QFoo  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) fex,z%}p  
public SiteFileFetch(SiteInfoBean bean) throws IOException -VT+O+9_A  
{ ig+4S[L~n  
siteInfoBean = bean; [[+ pMI  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); +TJ EG?o  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); GP a`e  
if(tmpFile.exists ()) c#cx>wq9  
{ k)7{Y9_No  
bFirst = false; X}A'Cg0y  
read_nPos(); t ^SzqB  
} eu#'SXSC F  
else _Z Y\,_  
{ "r'ozf2 \  
nStartPos = new long[bean.getNSplitter()]; |E)aT#$f'  
nEndPos = new long[bean.getNSplitter()]; \Qy$I-Du  
} ",Cr,;]  
PXk?aJ  
!L24+$  
,"2TArC'z  
} ~E5z"o6$  
q3P+9/6  
V 9;[M;  
public void run() 'T8W!&$  
{  Mps5Vv  
//获得文件长度 =^;P#kX  
//分割文件 `[fx yg:u  
//实例FileSplitterFetch .u z|/Zy  
//启动FileSplitterFetch线程 vbG]mMJ  
//等待子线程返回 BS 1Ap  
try{ B.dT)@Lx0  
if(bFirst) ('[TLHP  
{ kHK0(bYK  
nFileLength = getFileSize(); </`yd2>  
if(nFileLength == -1) 7'lZg<z{~j  
{ 2kh"8oQ  
System.err.println("File Length is not known!"); gm"#:< )  
} b #fTAC;<  
else if(nFileLength == -2) 8|^CK|m6*  
{ (eWPis[  
System.err.println("File is not access!"); 23]Y<->Eu<  
} OF U/gaO~  
else {KL5GowH  
{ ,  X{>  
for(int i=0;i<nStartPos.length;i++) Zu*K-ep"  
{ sW@krBxMv  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); h*i9m o  
}  C})'\1O%  
for(int i=0;i<nEndPos.length-1;i++) Zyf P; &  
{ wq!iV |  
nEndPos = nStartPos[i+1]; q(M:QWA q  
} <%?#AVU[  
nEndPos[nEndPos.length-1] = nFileLength; o4y']JSN  
} ~FU@wV^   
} eD?3"!c!  
j]rz] k  
uBrMk  
//启动子线程 DGESba\2+  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];  ;q>9W,jy  
for(int i=0;i<nStartPos.length;i++) zCaT tb|@  
{ XzIx:J6  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w?Ju5 5  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), R9+jW'[K  
nStartPos,nEndPos,i); V9NTs8LKc  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k?GD/$1t  
fileSplitterFetch.start(); iA }vKQ  
} 5s{j = .O  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;]2s,za)qs  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); SkQswH  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EbNd=Z'J  
nEndPos = " + nFileLength); Dh4 6o|P  
// fileSplitterFetch[nPos.length-1].start(); 8 .>/6M  
l`9t}  
0#o/^Ah  
//等待子线程结束 k(VB+k"3  
//int count = 0; ,5 j"ruZ  
//是否结束while循环 q!~ -(&S  
boolean breakWhile = false; a?h*eAAc.  
Hh;:`;}  
gY-5_Ab  
while(!bStop) 7r# ymQ  
{ k44Q):ncY7  
write_nPos(); 5*%#o  
Utility.sleep(500); "UFs~S|e  
breakWhile = true; ] y{WD=T  
OPJ: XbG  
Y$K!7Kq  
for(int i=0;i<nStartPos.length;i++) Cizvw'XDV  
{ igL<g  
if(!fileSplitterFetch.bDownOver) E>LkJSy=  
{ 5Z/7kU= I  
breakWhile = false; T4/fdORS  
break; w'4AJ Q|;  
} :nN1e  
} W*DVi_\$y  
if(breakWhile) =<@2#E)  
break; ! |waK~jK  
?4H#G)F  
Z6C=T;w  
//count++; @oP_;G  
//if(count>4) #65^w=Sp}  
// siteStop(); ? 8aaD>OR$  
} /wShUR{  
eYUr-rN+)z  
WUc#)EEM)  
System.err.println("文件下载结束!"); {~GYj%-^  
} Rgy- OA  
catch(Exception e){e.printStackTrace ();} f>o,N{|  
} inb^$v  
9I7\D8r  
}GMbBZ:nKK  
//获得文件长度 ^jB8Q  
public long getFileSize() RrZM&lXY  
{ }kHdK vZ  
int nFileLength = -1; ZIR0PQh\  
try{ P;[OWSR[d  
URL url = new URL(siteInfoBean.getSSiteURL()); 1F'1>Bu~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WO5O?jo'  
httpConnection.setRequestProperty("User-Agent","NetFox"); b3-e R5U/  
}TQ{`a@  
Am0{8 '  
int responseCode=httpConnection.getResponseCode(); Qhi '') Q  
if(responseCode>=400) Y/<lWbj*A  
{ '+>fFM,*B  
processErrorCode(responseCode); / O/`<  
return -2; //-2 represent access is error 7M_U2cd|TD  
} gbeghLP[?  
/I5X"x  
:AdDLpk3j  
String sHeader; -~[9U,  
/^{BUo  
7\z ZpPDV  
for(int i=1;;i++) c\6+=\  
{  9fnA  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YYEJph@06q  
//Utility.log(in.readLine()); %=AxJp!a  
sHeader=httpConnection.getHeaderFieldKey(i); zJDSbsc$%  
if(sHeader!=null) =o}"jVE  
{ &;,,H< p  
if(sHeader.equals("Content-Length")) z{"2S="  
{ lU^;Z 6f  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {CG_P,FO  
break; 3nZ9m  
} jCAC `  
} AsS$C&^  
else r)9Dy,  
break; unJid8Lo  
} 87%*+n:?*  
} EpS(o>'  
catch(IOException e){e.printStackTrace ();} jc[_I&Oc_  
catch(Exception e){e.printStackTrace ();} 8[CB>-9  
 |{* }|  
,mS/h~-5n  
Utility.log(nFileLength); t>GfM  
q+ KzIde|%  
"LYh7:0s!k  
return nFileLength; R3)57OyV  
} Q-Ux<#  
\l"&A  
%<?0apO  
//保存下载信息(文件指针位置) E5el?=,i  
private void write_nPos() _zt1 9%Wg  
{ - K%,^6  
try{ k%wn0Erd  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Xtz-\v#0o'  
output.writeInt(nStartPos.length); KTvzOI8  
for(int i=0;i<nStartPos.length;i++) pL1Q7&&c0  
{ 6iEhsL&K  
// output.writeLong(nPos); zf4Ec-)  
output.writeLong(fileSplitterFetch.nStartPos); fPi3s b`}  
output.writeLong(fileSplitterFetch.nEndPos); \T]EZ'+O  
} f\+f o  
output.close(); Qu5UVjbE,  
} L%v^s4@  
catch(IOException e){e.printStackTrace ();} ,uw132<b  
catch(Exception e){e.printStackTrace ();} ONNpiK-  
} ,:~0F^z  
6) oLus  
4Wy <?O2  
//读取保存的下载信息(文件指针位置) A7! g  
private void read_nPos() 72sD0)?A  
{ E3@QI?n^^  
try{ jztq.2-c#  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l$K,#P<)  
int nCount = input.readInt(); AM"Nn L"  
nStartPos = new long[nCount]; 4!asT;`'  
nEndPos = new long[nCount]; Q6o(']0  
for(int i=0;i<nStartPos.length;i++) R1F5-#?'E  
{ {7!UQrm<  
nStartPos = input.readLong(); )eUW5 tS  
nEndPos = input.readLong(); Zh5RwQNE~  
} p~ C.IG  
input.close(); VL[R(a6c <  
} -/_L*oYli  
catch(IOException e){e.printStackTrace ();} AC O)Dt(Y  
catch(Exception e){e.printStackTrace ();} GV)<Q^9  
} A^ _a3$,0  
OA:%lC!  
jENr>$$  
private void processErrorCode(int nErrorCode) O8|5KpXd@  
{ KZ!3j_pKy  
System.err.println("Error Code : " + nErrorCode); nd;fy$<J\  
} d!KsNkk  
1Z[/KJ  
| K?#$~  
//停止文件下载 ;})5:\h  
public void siteStop() 7'wS\/e4a  
{ Qr1e@ =B  
bStop = true; ZpUCfS)|&  
for(int i=0;i<nStartPos.length;i++) j8|g!>Nv  
fileSplitterFetch.splitterStop(); w ;daC(:  
hYQ_45Z*?  
*A}cL  
} g }laG8  
} st"{M\.p  
//负责部分文件的抓取 Oz|K8p  
**FileSplitterFetch.java b}T6v  
*/ zkTp`>9R  
package NetFox; |Iu npZV  
Ngb(F84H?  
v+jsC`m  
import java.io.*; KXV[OF&J  
import java.net.*; AtR?J"3E  
*lef=:&,,  
5XuT={o  
public class FileSplitterFetch extends Thread { ^Qu iH'  
?ER-25S  
{]z4k[;.h  
String sURL; //File URL ,!V]jP)  
long nStartPos; //File Snippet Start Position @&D?e:|!U  
long nEndPos; //File Snippet End Position ;> m"x  
int nThreadID; //Thread's ID X1 ZgSs+i  
boolean bDownOver = false; //Downing is over s >0Nr  
boolean bStop = false; //Stop identical [D5t{[i  
FileAccessI fileAccessI = null; //File Access interface 7_2kDDW0  
<foCb%$(?  
%>gW9}kB  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #W.vX?-'0  
{ y=Mq(c:'UN  
this.sURL = sURL; b':|uu*/  
this.nStartPos = nStart; }F+zs*S  
this.nEndPos = nEnd; Qu,8t 8  
nThreadID = id; d:G]1k;z  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I@Xn3oN  
} O]f/r,4@  
\rykBxs  
JQ :Ri  
public void run() E;21?`x5  
{ #,{+3Y&5-+  
while(nStartPos < nEndPos && !bStop) ^m_yf|D$  
{ nm7;ieMfr  
H:p Z-v*  
fYE(n8W3  
try{ /6O??6g  
URL url = new URL(sURL); 1FtM>&%4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uxg9yp@|  
httpConnection.setRequestProperty("User-Agent","NetFox"); X0 -IRJ[  
String sProperty = "bytes="+nStartPos+"-"; dD<fn9t  
httpConnection.setRequestProperty("RANGE",sProperty); TO2c"7td  
Utility.log(sProperty); v^ d]r Sm  
Jc)^49Rf  
U/lM\3v/e  
InputStream input = httpConnection.getInputStream(); nA?Hxos  
//logResponseHead(httpConnection); zrVC8Wb  
6h3HDFS7s  
u*  
byte[] b = new byte[1024]; azjEq$<M  
int nRead; y2O4I'/5<  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (Qgde6  
{ 2 xw6 5z  
nStartPos += fileAccessI.write(b,0,nRead); <8UYhGK  
//if(nThreadID == 1) iYnEwAoN;  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;,&8QcSVY  
} &[2U$`P`V  
+.y .Mp  
\D>$aLO*?  
Utility.log("Thread " + nThreadID + " is over!"); MxzLK%am  
bDownOver = true; Knhp*V?  
//nPos = fileAccessI.write (b,0,nRead); q9"=mO0J+  
} ,]}?.g  
catch(Exception e){e.printStackTrace ();} V|)>{Xdn  
} VL9-NfeqR  
} Y^%T}yTtq  
bVmA tm[  
~.%K/=wK@  
//打印回应的头信息 `V[!@b:  
public void logResponseHead(HttpURLConnection con) iut`7  
{ 5>J=YLq  
for(int i=1;;i++) U|G|l|Bl  
{ c:83LZ  
String header=con.getHeaderFieldKey(i); vd`}/~o  
if(header!=null) @H!$[m3  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g<*BLF  
Utility.log(header+" : "+con.getHeaderField(header)); )XQ`M?**M  
else ? muzU.h"z  
break; B= keBO](@  
} %LXM+<N8  
} e6=]m#O9  
 ]*O/+  
]CU]pK?nq  
public void splitterStop() >r &;3:"  
{ 9;yn}\N `  
bStop = true; 74<!&t  
} PNW \*;j  
7^} Ll@  
0iCPi)B  
} 1B*WfP~  
Qr# 1u  
k7tYa;C  
/* .^) UO  
**FileAccess.java 2!N8rHRt  
*//文件访问(定位,写) J==SZ v  
package NetFox; UR(-q  
import java.io.*; W~_t~Vg5  
}0,>2TTDN  
?}Z1(it0  
public class FileAccessI implements Serializable{ UEak^Mm;=2  
4Ij-Ilg)%  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i?Ss:v^  
RandomAccessFile oSavedFile; X\p,%hk \  
long nPos; \b}~2oX  
MH| ] \  
#6Xs.*b5C  
public FileAccessI() throws IOException P7B:%HiAx  
{ Qy#)Gxp  
this("",0); K}[>T(0E  
} \qsw"B*tv`  
dBO@6*N4c  
VC5_v62&.  
public FileAccessI(String sName,long nPos) throws IOException %tA57Pn>  
{ F>]#}_  
oSavedFile = new RandomAccessFile(sName,"rw"); eUS   
this.nPos = nPos; 'H9=J*9oG  
oSavedFile.seek(nPos); Bs`$ i ;&  
} c41: !u^  
PR<||"03  
fIoIW&iy  
public synchronized int write(byte[] b,int nStart,int nLen) h5 Vv:C  
{ +b;hBb]R  
int n = -1; W{XkV Ke1a  
try{ +@X5!S6  
oSavedFile.write(b,nStart,nLen); 5)1+~B  
n = nLen; ^EVc95|Z  
} {Hr$wa~  
catch(IOException e) wLuv6\E  
{ {|9}+ @5Q1  
e.printStackTrace (); 4t4olkK3Oa  
} "S~_[/q  
(_* wt]"'  
A`O<6   
return n; +.[\g|G  
} _9:@Vl]Q@  
xChI ,~i  
lA>\Ko  
} j:5%ppIY  
,1Qd\8N9  
31Cq22"  
/* i5hD#  
**SiteInfoBean.java G@S&1=nj3  
*/ ~;-9X|  
package NetFox; 9?+9UlJ7K  
mzL[/B#>M  
]O:M$ $  
public class SiteInfoBean { ps1YQ3Ep&  
;D ~L|  
lfk9+)  
private String sSiteURL; //Site's URL n)8Yj/5  
private String sFilePath; //Saved File's Path %R_{1GrL'c  
private String sFileName; //Saved File's Name m$>iS@R  
private int nSplitter; //Count of Splited Downloading File =fc: 6JR  
^ L:cjY/  
zH)_vW  
public SiteInfoBean() 9-*NW0  
{//nSplitter的缺省值为5 ]kktoP|D  
//default value of nSplitter is 5 B%<e FFV\  
this("","","",5); kL@Wb/K JP  
} dOa!htx]  
S_J :&9L  
"YFls#4H-  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h?@G$%2  
{ )tZ`K |  
sSiteURL= sURL; .M|>u_<Qd  
sFilePath = sPath; f<[jwhCWV  
sFileName = sName; i~=s^8n`l  
this.nSplitter = nSpiltter; l52a\/  
jSt mS2n  
k D~uGA  
} Y{Ap80'\6  
QHf$f@bjI  
g+q@i{Yn  
public String getSSiteURL() E|Bd>G  
{ $]d*0^J 6  
return sSiteURL; ^Uw[x\%#gD  
} p|6v~  
~JZ3a0$^  
O]u",J5  
public void setSSiteURL(String value) #,f{Ok+  
{ NlR"$  
sSiteURL = value; V:K;] h*!  
} <SXZx9A!  
#*IVlchA"B  
f %fa{  
public String getSFilePath() [p;*r)f2}  
{ %j]ST D.E  
return sFilePath; ,j9 80/  
} RpQ*!a~O  
='Oj4T  
H;vZm[\0N-  
public void setSFilePath(String value) QrjDF>   
{ i3V/`)iz  
sFilePath = value; Hw_o w?  
} [$:,-Q@  
"h$R ]~eG  
'% 4P;HO  
public String getSFileName() vgPUIxB@  
{ D(Ix!G/  
return sFileName; !c8L[/L  
} /J%do]PDl  
2YQ#-M  
i*tv,f.(  
public void setSFileName(String value) ~@c-*  
{ g,lY ut  
sFileName = value;  0%Q9}l#7  
} 8Pmwzpk02  
9 pKm*n&  
X BI;Lg  
public int getNSplitter() @6.]!U4w  
{ eqzTQen8q  
return nSplitter; lJ/6-dP  
} ~Yk"Hos  
+mWjBY  
*re 44  
public void setNSplitter(int nCount) 7c1+t_Ew  
{ 8GB]95JWwp  
nSplitter = nCount; ;<6"JP>0  
} b :\D\X  
} P.4E{.)(  
g^lFML| %  
.j 'wQ+_  
/* w!,QxrOV~  
**Utility.java D$pj#  
*/ 3z,2utH  
package NetFox; mCk5B*Jy  
E2:D(7(;l  
qzdaN5  
public class Utility { c cr" ep  
;~ee[W$1  
/Dd\PjIH{  
public Utility() pcpxe&S  
{ kyAs'R @z  
FLbZ9pX}  
Baq ~}B<  
} [}k|  
& l^n4  
//线程睡眠 BR3mAF  
public static void sleep(int nSecond) /RF%1!M K  
{ 1M+Zkak7p  
try{ NhlJ3/J j  
Thread.sleep(nSecond); 5ZsDgOeY  
} Sr7@buF  
catch(Exception e) m!!;/e?yx  
{ gE=Wcb!  
e.printStackTrace (); /#\?1)jCK  
} Y@:3 B:m#  
} m.1 46  
m^0A?jBrR  
//日志 Qv!rUiXq  
public static void log(String sMsg) pGk"3.ce  
{ eiB(VOJ  
System.err.println(sMsg); Q<'@V@H  
} \]a uSO  
PJwEA  
.HDebi  
public static void log(int sMsg) "o==4?*L  
{ =tq7z =k  
System.err.println(sMsg); E3tj/4:L  
} '}zT1F* p=  
} *^6k[3VY  
nOuN|q=C  
t'Htx1#Zc[  
/* cUM_ncYOP  
**TestMethod.java ] zIfC>@R  
*/ yy))Z0E5  
package NetFox; =#'+"+lQ }  
GU#Q}L2  
>0M:&NMda  
public class TestMethod { 0~.)GG%R>D  
z (#Xca  
C zpsqTQ  
public TestMethod() VVN # $  
{ ///xx/weblogic60b2_win.exe A?sNXhh  
try{ g\j>qUjs%Q  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g1dmkX  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :+1bg&wQ  
SiteFileFetch fileFetch = new SiteFileFetch(bean); JOgmF_(>Z  
fileFetch.start(); f-s~Q 4  
} kI]=&Rw  
catch(Exception e){e.printStackTrace ();} { "}+V`O{  
7(5]Ry:  
yHtGp%j  
} 8tC+ lc  
(V^QQ !:  
[BE:+ ID3  
public static void main(String[] args) )_F(H)*  
{ X%35XC.n  
new TestMethod(); & ]%\.m  
} 6i^0T  
} ~CulFxu  
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