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http断点续传简单实现(java)

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/* 77``8,  
**SiteFileFetch.java %Hh3u$Y,  
*/ SAP;9*f1\  
package NetFox; Pow|:Lau!  
import java.io.*; >Z}@7$(7!~  
import java.net.*; mLJDxh'B  
Y7-*2"!  
Cgo9rC~]  
public class SiteFileFetch extends Thread { L4~ W/6A  
&%6NQWW  
N.jA 8X  
SiteInfoBean siteInfoBean = null; //文件信息Bean sqT^t!  
long[] nStartPos; //开始位置 97!H`|u <  
long[] nEndPos; //结束位置 rxs8De  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 )]wuF`  
long nFileLength; //文件长度 YtMlqF  
boolean bFirst = true; //是否第一次取文件 "i&fp:E0  
boolean bStop = false; //停止标志 YhS{$ Z  
File tmpFile; //文件下载的临时信息 Gp,'kw"I  
DataOutputStream output; //输出到文件的输出流 <E SvvTf  
4HW;  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) q4) Ey  
public SiteFileFetch(SiteInfoBean bean) throws IOException J=@xAVBc  
{ Jns/v6  
siteInfoBean = bean;  f -7S:,  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); VxkEez'|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); KYf;_C,$  
if(tmpFile.exists ()) AO $Wy@  
{ g#}tm<  
bFirst = false; Uh}+"h5  
read_nPos(); o~;M"  
} 3 tF:  
else z#RuwB+  
{ ).Q[!lly   
nStartPos = new long[bean.getNSplitter()]; {d,?bs)  
nEndPos = new long[bean.getNSplitter()]; ?]5Ix1  
} -8/JP  
C;ptir1G;  
/eb-'m  
7/ t:YBR  
} gX_SKy  
/~tP7<7A  
H~eGgm;p  
public void run() %7 /,m  
{ xvB8YW"  
//获得文件长度 :mP9^Do2;  
//分割文件 "Vx6 #u@}  
//实例FileSplitterFetch 1LX)4TCC  
//启动FileSplitterFetch线程 V,vc_d?,_o  
//等待子线程返回 @%:E  }  
try{ [Teh*CV  
if(bFirst) M|H 2kvl  
{ ++0rF\&  
nFileLength = getFileSize(); cl_T F[n?  
if(nFileLength == -1) &}E:jt}  
{ ,WGc7NN`  
System.err.println("File Length is not known!"); 6<PW./rk:  
} Wt:~S/l  
else if(nFileLength == -2) x)$2nonM  
{ %jT w  
System.err.println("File is not access!"); WGPD8.  
} KGD'mByt"  
else /=@e &e  
{ \C7q4p?8  
for(int i=0;i<nStartPos.length;i++) B$j' /e-Zk  
{ W"t"X ~T3  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,\x$q'  
} W "k| K:  
for(int i=0;i<nEndPos.length-1;i++) 4kh8W~i;/  
{ jqtVpNwM  
nEndPos = nStartPos[i+1]; c$A@T~$  
} @h9K  
nEndPos[nEndPos.length-1] = nFileLength; %I0}4$  
} cWM:  
} 1yS&~ y?a  
0MrN:M2B  
"koo` J  
//启动子线程 |T y=7d,  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \%4|t,en  
for(int i=0;i<nStartPos.length;i++) EZ{\D!_Y  
{ "k, K~@}  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U!Mf]3  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~of,,&  
nStartPos,nEndPos,i); * :S~C  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d"GDZ[6  
fileSplitterFetch.start(); GXYj+ qJ  
} +A\V)  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \4QH/e  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vpV$$=Qwp  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?;RD u[eD  
nEndPos = " + nFileLength); 61>f(?s  
// fileSplitterFetch[nPos.length-1].start(); zR/IqW.`9  
S(tEw Xy  
[xf$VkjuF  
//等待子线程结束 Z'ao[CG  
//int count = 0; ;W~4L+e  
//是否结束while循环 {2 EMz|&8  
boolean breakWhile = false; HzEGq,.  
Z /h|\SyJ  
p&O8qAaO  
while(!bStop) OfJd/D  
{ GMe0;StT  
write_nPos(); 7H#2WFQ7  
Utility.sleep(500); kC31$jMC3!  
breakWhile = true; x=vK EyS@  
yKlU6t&` G  
0e\y~#-  
for(int i=0;i<nStartPos.length;i++) 8JP6M!F#  
{ z{/LX \  
if(!fileSplitterFetch.bDownOver) 2`E! |X  
{ D:)~%wu Lt  
breakWhile = false; <p/MyqZf  
break; #<]Iz'\`  
} vnZ4(  
} zQ<88E&&Xs  
if(breakWhile) 506V0]`/  
break; 3(o7co-f  
{lMqcK  
E|{m"RUOy  
//count++; k% NrL@z  
//if(count>4) Bz:&f46{  
// siteStop(); LyV#j>gD  
} bM5CDzH(#X  
@Kp1k> ov  
!-ZP*V3}h  
System.err.println("文件下载结束!"); K-6p'|  
} zWtj|%ts  
catch(Exception e){e.printStackTrace ();} F3 Y<ZbxT  
} 7j T#BWt  
|,{+;:  
QY6O(=  
//获得文件长度 RQ|?Ce",  
public long getFileSize() NA\x<  
{ *0\k Z,#BJ  
int nFileLength = -1; $bFgsy*N2  
try{ F^xaz^=`u  
URL url = new URL(siteInfoBean.getSSiteURL()); ) G|"jFP  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^Eu_NUFe  
httpConnection.setRequestProperty("User-Agent","NetFox"); @ct#s:t  
}H; ]k-)  
F'XlJ M  
int responseCode=httpConnection.getResponseCode(); f}%sO  
if(responseCode>=400) /3s@6Ex}E  
{ M&OsRrq  
processErrorCode(responseCode); ]o `4Z"  
return -2; //-2 represent access is error s<,"Hsh^CR  
} TG?fUD V  
g4Bg6<;  
[d\#[l_  
String sHeader; 3}yraX6r!  
6kC)\ uy  
GV=V^Fl .  
for(int i=1;;i++) ;2BPPZ  
{ f!(cD80  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r &=r/k2  
//Utility.log(in.readLine()); Etdd\^  
sHeader=httpConnection.getHeaderFieldKey(i); ijg,'a~3E  
if(sHeader!=null) F\:{}782u  
{ L^&do98  
if(sHeader.equals("Content-Length")) ^,>}%1\  
{ nMeSCX  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2AmR(vVa"  
break; } cRi A  
} 8`6 LMQ  
} N0=b[%g;n  
else %uF:)   
break; b\H/-7<  
} WI%zr2T  
} 2 e )  
catch(IOException e){e.printStackTrace ();} WtMcI>4w  
catch(Exception e){e.printStackTrace ();} VB}PNg  
g}^4^88=a  
!P+~ c0DF  
Utility.log(nFileLength); ^j1Gmv)  
6CCZda@  
e$gaE</  
return nFileLength; +W!'B r  
} CdE2w?1  
J*/$ywI  
L>eQ*311  
//保存下载信息(文件指针位置) P^i6MZ?   
private void write_nPos() PsacXZNs\N  
{ ~y( ,EO  
try{ :+kg4v&r  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,!xz*o+#@  
output.writeInt(nStartPos.length); Z{Lmd`<w`j  
for(int i=0;i<nStartPos.length;i++) &:IfhS  
{ i+kFL$N  
// output.writeLong(nPos); ZK W@pW]U  
output.writeLong(fileSplitterFetch.nStartPos); [J(@$Qix  
output.writeLong(fileSplitterFetch.nEndPos); BHIZHp  
} RI7qsm6RN  
output.close(); P TfN+  
} sASAsGk<  
catch(IOException e){e.printStackTrace ();} /r #b  
catch(Exception e){e.printStackTrace ();} Y0R\u\b  
} My`josJ`Pb  
'` BjRg57]  
(Q*2dd>  
//读取保存的下载信息(文件指针位置) ljaAB+  
private void read_nPos() `Pz!SJ|  
{ !xJLeQFJI]  
try{ )of5229  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xF\}.OfWG  
int nCount = input.readInt(); VuYWb)@  
nStartPos = new long[nCount]; zM3H@;}m  
nEndPos = new long[nCount]; a,F8+ Pb>  
for(int i=0;i<nStartPos.length;i++) fJ|Bu("N  
{ ru(?a~lF8~  
nStartPos = input.readLong(); tIgCF?  
nEndPos = input.readLong(); |TNiKy  
} 83p$!8]u  
input.close(); N7Z(lI|a;  
} g(z#h$@S  
catch(IOException e){e.printStackTrace ();} f6(9wz$Trt  
catch(Exception e){e.printStackTrace ();} dd @COP?  
} Y'+F0IZ+  
8 H$@Xts  
P5ESrZ@f  
private void processErrorCode(int nErrorCode) <*b]JY V@  
{ &})4?5  
System.err.println("Error Code : " + nErrorCode); PEwW*4Xo  
} l72i e  
_z_3%N  
ZQJw2LAgO  
//停止文件下载 qU /Wg  
public void siteStop() |n-a\  
{ [h2p8i 'o  
bStop = true; #7cf 8y  
for(int i=0;i<nStartPos.length;i++) 8m1 3M5r  
fileSplitterFetch.splitterStop(); !@]h@MC$7  
}X W#?l  
=":V WHf  
} ^0BF2&Zx  
} ADwwiq#E  
//负责部分文件的抓取 2kmna/Qa6  
**FileSplitterFetch.java f@x( ,p  
*/ 8zB+%mcF  
package NetFox; =>9.@`.  
)4o=t.O\K  
q}7Df!<|  
import java.io.*; UU:QK{{E  
import java.net.*; w!GU~0~3[  
*M**h-p2'  
2Yg[8Tm#  
public class FileSplitterFetch extends Thread { MM58w3Mz  
q5K/+N^2?  
EF7|%N  
String sURL; //File URL '=G<)z@k  
long nStartPos; //File Snippet Start Position d9e H}#OY  
long nEndPos; //File Snippet End Position f^yLwRUD  
int nThreadID; //Thread's ID 0 S`b;f  
boolean bDownOver = false; //Downing is over IB]VPj5  
boolean bStop = false; //Stop identical N6 }i>";_;  
FileAccessI fileAccessI = null; //File Access interface `X]2iz  
iTBhLg,  
gCBZA;/  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "=5vgg3  
{ M6>\R$  
this.sURL = sURL; [2fiHE  
this.nStartPos = nStart; pa> 2JF*  
this.nEndPos = nEnd; DuC u6j  
nThreadID = id; ~4 xBa:*z  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Zo638*32  
} :Tl6:=B  
)bN3-_  
.^+$w $  
public void run() 5<GRi "7A@  
{ EpS8,[w  
while(nStartPos < nEndPos && !bStop) _/w-gL{  
{ ST [1'T+L  
-"^WDs  
Y Z2VP  
try{ y.]]V"'2  
URL url = new URL(sURL); ~X(xa  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c o%_~xO  
httpConnection.setRequestProperty("User-Agent","NetFox");  ,8 NEnB  
String sProperty = "bytes="+nStartPos+"-"; 1R~WY'Ed  
httpConnection.setRequestProperty("RANGE",sProperty); +Q#Qu0_   
Utility.log(sProperty); )aA9z(x  
-v+^x`HR  
u#k6v\/  
InputStream input = httpConnection.getInputStream(); }c#/1J7  
//logResponseHead(httpConnection); %+W >+xRb  
f?I *`~k  
%L|bF"K5;  
byte[] b = new byte[1024]; s=@Ce V@4W  
int nRead; HnY"6gTNK  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rxk{Li<9  
{ KIl.?_61O  
nStartPos += fileAccessI.write(b,0,nRead); [k{iN1n  
//if(nThreadID == 1) 1E_Ui1[  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c89vx 9  
} /g7?,/vnZ  
"LaX_0t)  
P&`r87J  
Utility.log("Thread " + nThreadID + " is over!"); /<(ik&%N  
bDownOver = true; S&) >w5*]U  
//nPos = fileAccessI.write (b,0,nRead); *pUV-^uo  
} x#VUEu]8  
catch(Exception e){e.printStackTrace ();} nL20}"$E  
} &bgi0)>  
} V xs`w  
Z_WTMs:x!  
Z6@J-<u  
//打印回应的头信息 ?bDae%>.d,  
public void logResponseHead(HttpURLConnection con) [t) i\ }V  
{ ;@s~t:u  
for(int i=1;;i++) oT{yttSNo  
{ ''07Km@x  
String header=con.getHeaderFieldKey(i); ,PxQ[CGg  
if(header!=null) ^#nWgo7{7  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3+uoK f[  
Utility.log(header+" : "+con.getHeaderField(header)); LbknSy C  
else " CoR?[,x  
break; *9 wHH-#  
} nQ3goVRFP  
} ; O0rt1  
o@;_(knb  
ebK wCZwK*  
public void splitterStop() TBT*j&!L  
{ Q kpmPQK  
bStop = true; Khd,|pM  
} UH|.@7w  
t+q`h3  
@!O{>`  
} S6X<3L`FfH  
T bWZw  
+N_%|!F-c  
/*  gOAluP  
**FileAccess.java VbR.tz  
*//文件访问(定位,写) @1Lc`;Wd  
package NetFox; ibw;BU  
import java.io.*; ?\r3 _  
]~ UkD*Ct  
XePBA J  
public class FileAccessI implements Serializable{ pjM|}i<'Q  
ir#^5e @  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KL`>mJo$  
RandomAccessFile oSavedFile; E1_4\ S*z  
long nPos; tn1aH +  
2jC\yY |PN  
ro@BmRMW  
public FileAccessI() throws IOException #9Z-Hd<  
{ SiT &p  
this("",0); i[#Tn52D  
} $0t %}DE  
Q2=~  
VRt*!v<")  
public FileAccessI(String sName,long nPos) throws IOException >m!.l{*j>N  
{ =T]OYk  
oSavedFile = new RandomAccessFile(sName,"rw"); K e8cfd~c  
this.nPos = nPos; _3S{n=9  
oSavedFile.seek(nPos); pnU g:R@  
} .YRSd  
(C%'I  
,YTIYG](  
public synchronized int write(byte[] b,int nStart,int nLen) k_B^2=  
{ 1-#tx*>AY  
int n = -1; ~T~v*'_h  
try{ KK6YA  
oSavedFile.write(b,nStart,nLen); !TF VBK  
n = nLen; 0*^Fk=>ej  
} aJ5R0Y,  
catch(IOException e) L?fv5 S3  
{ rGWTpN  
e.printStackTrace (); 8h97~$7)  
} 7Go!W(8  
25L{bcng  
UsTPNQj  
return n; wah`  
} 85mQHZ8aR  
b}:Z(L,\  
RAC-;~$WB  
} (Wn'.|^%  
*)<tyIHd  
OBZj-`fqJ  
/* jVz1`\Nje  
**SiteInfoBean.java \<} nn?~n  
*/ UL/>t}AG  
package NetFox; ?6dtvz;K+?  
,n*.Yq  
|}; ~YMH  
public class SiteInfoBean { !NCT) #G`  
WxFjpJt  
B.?yHaMI[  
private String sSiteURL; //Site's URL /Q!F/HY3ZS  
private String sFilePath; //Saved File's Path vF,l?cU~  
private String sFileName; //Saved File's Name ($wYaw z  
private int nSplitter; //Count of Splited Downloading File C N"c  
zkMQ= ,[  
dY,'6 JzC  
public SiteInfoBean() 2Y+*vNs3  
{//nSplitter的缺省值为5 fHigLL0B  
//default value of nSplitter is 5 61'7b`:(hi  
this("","","",5); Aq"_hjp  
} AOe~VW  
4v>V7T.  
MPt7 /  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F!xK#~e   
{ S;])Nt'X'  
sSiteURL= sURL; URAipLvN  
sFilePath = sPath; EVf'1^f  
sFileName = sName; J.<m@\U  
this.nSplitter = nSpiltter; lwU&jo*@  
`&_qK~&/X  
Z8 T{Xw6%  
} =9c24j  
-4Xr5j%o  
Pc3u`QL?  
public String getSSiteURL() <n>< A+D  
{ BWs\'B  
return sSiteURL; 6"DvdJ0MB  
} r#XDgZtI  
p})&Zl)V  
R:e:B7O~0  
public void setSSiteURL(String value) R9W(MLe58  
{ G2Apm`/ y  
sSiteURL = value; +|.#<]GA  
} O/k4W#  
8[DD=[&  
t~AesHZpk  
public String getSFilePath() j<!$ug9VA  
{ gFKQm(0g2  
return sFilePath; GB+G1w  
} +LUL-d  
Xm*Dh#H  
ecHy. 7H  
public void setSFilePath(String value) <W?,n%  
{ r[gV`khka  
sFilePath = value; S2*:]pYf}  
} !B\\:k]aO^  
[)*fN|Hy  
dI>oHMC  
public String getSFileName() b#P8Je`;9  
{ ENGw <  
return sFileName; 3{%/1>+x5  
} 8\yH 7H  
u%|VmM>  
Kg.E~  
public void setSFileName(String value) :g,rl\S7  
{ =v_ju;C=  
sFileName = value; %|;^[^7+}t  
} _ pJU~8  
8^^al!0K~  
mU3UQ j  
public int getNSplitter() tuv4~i<  
{ B^6P 6,  
return nSplitter; rOcfPLJi0  
} (s9?#t6  
9oaq%Sf  
N%T-Q9k  
public void setNSplitter(int nCount) k<:!^_3H  
{ ic3qb<2  
nSplitter = nCount; eQ*gnV}rE%  
} lFB Ka ,6  
} ~[[a7$_4  
@ O%m,  
P[Qr[74 )  
/* !Zs;m`j&9  
**Utility.java L\b$1U!i  
*/ bT8BJY%+  
package NetFox; J +9D/VT  
QZDGk4GG  
sT/pA^rnnR  
public class Utility { v+\E%H  
mX<D]Z< k  
 fBQZ=zh  
public Utility() ok7DI  
{ B[k"xs  
Uqkh@-6-  
%D&FnTa  
} `E}2|9  
//WgK{Mt  
//线程睡眠 MM^tk{2?.  
public static void sleep(int nSecond) (US8Sc  
{ M14pg0Q  
try{ zis-}K<   
Thread.sleep(nSecond); Vv zd>yII  
} SK-|O9Ki  
catch(Exception e) z`TI<B  
{ H-I*;  
e.printStackTrace (); >f_D|;EV  
} 9%)'QDVGLf  
} }3+q}_3  
RRV&!<l@$  
//日志 Ir]b. 6B  
public static void log(String sMsg) FCI38?`%  
{ JhuK W>7  
System.err.println(sMsg); _Jx?m  
} >q]r)~8F^  
*gBaF/C  
L*FnFRhU  
public static void log(int sMsg) }p "HD R>  
{ _msDf2e9  
System.err.println(sMsg); Va9vDb6  
} {Q4=GrS  
} dAga(<K  
vnIxI a  
71f]KalqL  
/* X5)>yM^N`  
**TestMethod.java n+xM))  
*/ RPLr7Lb  
package NetFox; !lHsJ)t  
TzPVO>s  
 dedi6Brl  
public class TestMethod { m 81\cg  
}De)_E\~  
\2~.r/`1  
public TestMethod() fV[xv4D.  
{ ///xx/weblogic60b2_win.exe /ZD/!YD&R  
try{ 1f~_# EIC  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QI!:+8  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L9G=+T9  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;M}bQ88  
fileFetch.start(); .p0;y3so4  
} J,jl(=G  
catch(Exception e){e.printStackTrace ();} 23Eg|Xk  
heRQ|n.Dz)  
8lbNw_U  
} $|A vT;4  
ncihc$V<  
}_u )3X.O  
public static void main(String[] args) 'zRd?Z>%  
{ a)} ?rzT]  
new TestMethod(); g%^Zq"  
} 6"gncB.  
} b}[{'  
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