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http断点续传简单实现(java)

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/* JWHS nu!  
**SiteFileFetch.java #MgvG,  
*/ J)x3\[}Ye  
package NetFox; c{3rl;Cs  
import java.io.*; s: |M].  
import java.net.*; y!Cc?$]_Y  
^^?q$1k6r*  
l},NcPL`  
public class SiteFileFetch extends Thread { gA^q^>7  
8b&uU [  
,Ww  
SiteInfoBean siteInfoBean = null; //文件信息Bean SBfFZw)  
long[] nStartPos; //开始位置 #Ob]]!y  
long[] nEndPos; //结束位置 T{Zwm!s  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 v%91k  
long nFileLength; //文件长度 =!.m GW-Q}  
boolean bFirst = true; //是否第一次取文件 (Wj2?k/]  
boolean bStop = false; //停止标志 -G`.y?  
File tmpFile; //文件下载的临时信息 Dz&+PES_k  
DataOutputStream output; //输出到文件的输出流 jPJAWXB4a  
Fwfo2   
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) *y7 $xa4  
public SiteFileFetch(SiteInfoBean bean) throws IOException Z[L5 ;  
{ H5xzD9K;/C  
siteInfoBean = bean; x0+glQrNN  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); LI W*4r!  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); iS: #o>  
if(tmpFile.exists ()) P%>?[9!Nt  
{ v,1F-- v  
bFirst = false; $ |<m9CW  
read_nPos(); >S#ul?  
}  tFh|V pB  
else I$jvXl=$  
{ ijYvqZ_  
nStartPos = new long[bean.getNSplitter()]; .ER98  
nEndPos = new long[bean.getNSplitter()]; N}Vn;29  
} _m'ysCjA  
fE;Q:# Z.  
8A2 z 5Aa  
"> 90E^  
} t1i(;|8|  
[xaisXvI4  
L\  j:  
public void run() wGLF%;rRe4  
{ Dkw7]9Qm  
//获得文件长度 SI-X[xf  
//分割文件 eBcJm  
//实例FileSplitterFetch l5O=VqCj  
//启动FileSplitterFetch线程 o /p-!  
//等待子线程返回 F[E? A95W  
try{ #g v4  
if(bFirst) {NQo S"  
{ 49h0^;xlo:  
nFileLength = getFileSize(); ef]B9J~h  
if(nFileLength == -1) w6zB Vi  
{ 6?gi_3g  
System.err.println("File Length is not known!"); )"u:ytK{  
} V2 `> ]/|  
else if(nFileLength == -2) n9oR)&:o  
{ b|?;h21rG  
System.err.println("File is not access!"); optBA3@e!  
} z +VV}:Q  
else G[yI*/E;  
{ Zf:]Gq1  
for(int i=0;i<nStartPos.length;i++) >Y&KTSD"  
{ U{#xW  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); iuAq.$oi{  
} \ P/W8{  
for(int i=0;i<nEndPos.length-1;i++) ; B$ *)X9  
{ L.)yXuo4  
nEndPos = nStartPos[i+1]; |C-y}iQ:6~  
} :5# V^\3*  
nEndPos[nEndPos.length-1] = nFileLength; TOT PzB  
} S/Oxr%H  
} oXGZK5w<l  
MCy~@)-IN  
! D1zXXq  
//启动子线程 !nw [  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YoSQN/Z  
for(int i=0;i<nStartPos.length;i++) @ss):FwA  
{ +R\~3uj[7  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 36A;!1  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EXbTCT}`x  
nStartPos,nEndPos,i); p\D >z("  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V SAafux  
fileSplitterFetch.start(); =vEkMJ Os  
} Zu#<  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ay$>(;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u,9q<&,  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =cp;Q,t'9L  
nEndPos = " + nFileLength); #7W.s!#}Dd  
// fileSplitterFetch[nPos.length-1].start(); 2d&^Sp&11  
0XIxwc0Iw  
I'InZ0J2  
//等待子线程结束 AQh["1{yJ  
//int count = 0; 8S>>7z!U  
//是否结束while循环 {D(,ft;s^  
boolean breakWhile = false; yazZw}};  
3$_2weZxYn  
UR:n5V4  
while(!bStop) ScJu_A f  
{ 6>B \|  
write_nPos(); fPz=KoN  
Utility.sleep(500); `:5,e/5,  
breakWhile = true; Vy;_GfT$  
T`Hw49  
+x]e-P%  
for(int i=0;i<nStartPos.length;i++) C*pLq5s  
{ uUS)#qM |  
if(!fileSplitterFetch.bDownOver) ^ f{qJ[,  
{ Q8Te'1Ln!  
breakWhile = false; l1RlYl5  
break; `|,tCM&-  
} AM/lbMr  
} l<N?'&  
if(breakWhile)  -$R5  
break; P"Rk?lL  
/Ynt<S9"  
UK:M:9  
//count++; 0w}{(P;  
//if(count>4) ]h8/M7k  
// siteStop(); L>:FGNf^H  
} m X:bA5db  
"1%*'B^}bw  
cYD1~JX.  
System.err.println("文件下载结束!"); `~E<Sf<M  
} 5f3!NeI  
catch(Exception e){e.printStackTrace ();} *a4 b  
} :SeLkQC  
V8v,jS$l4  
Wa/geQE1<  
//获得文件长度 mxhW|}_-j  
public long getFileSize() OfLM  
{ ]+,nA R  
int nFileLength = -1; 9OZ>y0)K~  
try{ )$F6  
URL url = new URL(siteInfoBean.getSSiteURL()); 1gAc,s2  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z1qUz7  
httpConnection.setRequestProperty("User-Agent","NetFox"); 05g?jV  
my=~"bw4  
-faw:  
int responseCode=httpConnection.getResponseCode(); #tP )-ww  
if(responseCode>=400) Iq@IUFpc7~  
{ 44|03Ty  
processErrorCode(responseCode); 6\mC$:F  
return -2; //-2 represent access is error 2w7@u/OC'  
} 9BurjG1k?  
_!;\R7]  
%\_h7:  
String sHeader; gyg|Tno  
4sQ~&@[Q+  
Bf(Mot^  
for(int i=1;;i++) )#mW7m9M#  
{ !$XO U'n  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G`WzJS*}v  
//Utility.log(in.readLine()); #nDL  
sHeader=httpConnection.getHeaderFieldKey(i); 5Wl,J _<F  
if(sHeader!=null) (ai72#nFtb  
{ C64eDX^  
if(sHeader.equals("Content-Length")) -%N}A3m!5  
{ wEv*1y4  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rl41# 6  
break; a6 * Y%?  
} {cX7<7N  
} B8>FCF&}E  
else 2nYiG)tg  
break; "$4hv6 s  
} GZ.?MnG  
} -ca]Q|m8  
catch(IOException e){e.printStackTrace ();} 81cv:|"  
catch(Exception e){e.printStackTrace ();} tTE3H_   
=b|)Wnt2f  
s}<)B RZi  
Utility.log(nFileLength); B##C{^5A`  
P'gT6*an,"  
v3 !byN^  
return nFileLength; = c/3^e  
} O]4W|WI3  
#SK#k<&P  
U8U/?zW/&  
//保存下载信息(文件指针位置) >n#g9vK  
private void write_nPos() Yoj~|qL  
{ 18J.vcP  
try{ JJ*0M(GG  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^glbxbhI4  
output.writeInt(nStartPos.length); 1h& )I%`?  
for(int i=0;i<nStartPos.length;i++) )m oo?Q  
{ Py}!C@e  
// output.writeLong(nPos); \qRjXadj  
output.writeLong(fileSplitterFetch.nStartPos); nqUH6(  
output.writeLong(fileSplitterFetch.nEndPos); #r-j.f}yx  
} 0 [*nAo  
output.close(); -aTg>Q|g&  
} Z={UM/6w  
catch(IOException e){e.printStackTrace ();} OME!W w  
catch(Exception e){e.printStackTrace ();} mJ7 `.  
} /0X0#+kn  
|~Htj4K/  
LAOdH/*:  
//读取保存的下载信息(文件指针位置) LZ3rr-  
private void read_nPos() #wq;^)>  
{ q^Q|.&_k /  
try{ M ^ 0w/  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WX+< 4j  
int nCount = input.readInt(); FA<Z37:  
nStartPos = new long[nCount]; Z 5{*? 2  
nEndPos = new long[nCount]; xF2f/y   
for(int i=0;i<nStartPos.length;i++) "`y W]v  
{  m,xy4  
nStartPos = input.readLong(); *S,v$ VX  
nEndPos = input.readLong(); ,S7~=S  
} :qt82tbn  
input.close(); k4]R]=Fh.  
} +5N^TnBtBL  
catch(IOException e){e.printStackTrace ();} KzxW?Ji$S  
catch(Exception e){e.printStackTrace ();} Hz8Jgp  
} rjhs ?  
9F-ViDI.  
Qu,)wfp~  
private void processErrorCode(int nErrorCode) hqwz~Ky}  
{ 3ZT/>a>@  
System.err.println("Error Code : " + nErrorCode); 0e[ tKn(  
} 5)/4)0  
c"oQ/x  
\= )[  
//停止文件下载 (\[jf39e  
public void siteStop()  3D[:Rf[  
{ ROlzs}  
bStop = true; 9;m#>a@Y  
for(int i=0;i<nStartPos.length;i++) :y<Cd[/  
fileSplitterFetch.splitterStop(); <S:,`v&Z  
hO:)=}+H  
=6L :I x  
} ^D>/wX\u  
} ;[;S_|vZ=)  
//负责部分文件的抓取 P:bVcta9g  
**FileSplitterFetch.java x);?jxd  
*/ 61t-  
package NetFox; )dzjz%B)  
^5^ zo~^o  
TZ`]#^kU  
import java.io.*; )%nt61P\W  
import java.net.*; &B{Jxc`VA  
FW6E)df  
f%(e,KgW=  
public class FileSplitterFetch extends Thread { \?p9qR;"4  
J$eZLj  
T`(;;%  
String sURL; //File URL B7x"ef  
long nStartPos; //File Snippet Start Position eO"\UDBV  
long nEndPos; //File Snippet End Position }]Z,\lA  
int nThreadID; //Thread's ID 'J&@jp  
boolean bDownOver = false; //Downing is over cfO^CC  
boolean bStop = false; //Stop identical Kuzy&NI^w  
FileAccessI fileAccessI = null; //File Access interface &6~ncQWu  
4 I]/  
=Un6|]  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &<[]X@ bY  
{ qjdahVY  
this.sURL = sURL; q>Ar.5&M_  
this.nStartPos = nStart; `G:qtHn"Q<  
this.nEndPos = nEnd; ?_<UOb*  
nThreadID = id; ~O7cUsAi'  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 da7x 1n$D  
} uDMUy"8&!  
z; z'`A  
FC/>L  
public void run() "KQ\F0/  
{ o*5e14W(:  
while(nStartPos < nEndPos && !bStop) ~[bMfkc3  
{ G~mB=]  
E l8.D3  
 Lqf#,J  
try{ 83O^e&Bt  
URL url = new URL(sURL); pCud` :o"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZLFdnC@  
httpConnection.setRequestProperty("User-Agent","NetFox"); J{'zkR?Lr  
String sProperty = "bytes="+nStartPos+"-"; cJp1 <R  
httpConnection.setRequestProperty("RANGE",sProperty); Dv\:b*  
Utility.log(sProperty); ^FpiQF  
=[CS2VQ'  
jP{]LJ2.6\  
InputStream input = httpConnection.getInputStream(); <:_]Yl  
//logResponseHead(httpConnection); DIcyXZH<  
*U[Q=w  
p|O-I&Xd  
byte[] b = new byte[1024]; XP Iu]F  
int nRead; +~v3D^L15  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .L 5T4)  
{ 2H32wpY ,l  
nStartPos += fileAccessI.write(b,0,nRead); 9FR1Bruf  
//if(nThreadID == 1) +'6ea+$  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z_ FL=S\  
}  ~d<`L[  
iLQt9Hyk  
HS7 G_  
Utility.log("Thread " + nThreadID + " is over!"); V,* 0<7h  
bDownOver = true; ?@uK s4  
//nPos = fileAccessI.write (b,0,nRead); ?PU(<A+  
} ,`B>}  
catch(Exception e){e.printStackTrace ();} j2v[-N4 {J  
} 2/<WWfX'  
} ;V(}F!U\z  
'Q;?_,`  
k=q%FlE  
//打印回应的头信息 `OpC-Z&  
public void logResponseHead(HttpURLConnection con) C Wl95g  
{ jwE(]u  
for(int i=1;;i++) Fq\`1Ee{  
{ J*4_|j;Z-E  
String header=con.getHeaderFieldKey(i); 3@WI*PMc  
if(header!=null) "u$ ]q1S  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d'@H@  
Utility.log(header+" : "+con.getHeaderField(header)); Fl|&eO,e  
else EO!cv,[a  
break; 1*`JcUn,>  
} IfI$  
} L08;z  
5~rY=0t  
T!eh?^E  
public void splitterStop() 8X~vJ^X9@y  
{ 5r}(|86O/  
bStop = true; `uJ l<kHI  
} L\'qAfRZ  
O%h 97^%k  
w+TuS).  
} *gMP_I  
j`-y"6)  
|^9ig_k`  
/* !urd $Ta  
**FileAccess.java [tw<TV"\  
*//文件访问(定位,写) N#-\JlJ)  
package NetFox; 9'L0Al~L  
import java.io.*; Q X5#$-H@  
thboHPml{  
g,]5&C T3v  
public class FileAccessI implements Serializable{ -VT?/=Y s  
zpQ/E  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fi@+swfc  
RandomAccessFile oSavedFile; kFs kn55  
long nPos; UDqKF85H  
iKTU28x  
_=$!T;}lE  
public FileAccessI() throws IOException z_0lMX`  
{ T%#P??k  
this("",0); V<I${i$]0  
} L |G k}n  
;,hoX6D$  
>" 8j{ s  
public FileAccessI(String sName,long nPos) throws IOException }K]VlFR  
{ i'LTKj  
oSavedFile = new RandomAccessFile(sName,"rw"); *bC^X'  
this.nPos = nPos; }^bL'  
oSavedFile.seek(nPos); 3 AF]en  
} |(8h:g  
w!k4&Rb3  
J0 z0%p   
public synchronized int write(byte[] b,int nStart,int nLen) ">^]^wa08  
{ >~8Df61o`  
int n = -1; b4OR`dd*J  
try{ C+IE<=%F  
oSavedFile.write(b,nStart,nLen); cr;`0  
n = nLen; :iC\#i]6  
} VNot4 62L  
catch(IOException e) 1:Gd{z  
{ 5"]2@@b4  
e.printStackTrace (); +>%+r  
} )Ea_:C'  
Xr;noV-X  
W3j|%  
return n; l[0P*(I,  
} 6spk* 8e  
u(a&x|WY  
c<x6_H6[8  
} HcUz2Rm5XP  
K1WoIv<Ym  
 -KiS6$-  
/* uk/+ i`=  
**SiteInfoBean.java DfFPGFv  
*/  0PbIWy'  
package NetFox; =5eDT~=2{U  
2= mD  
vw6FvE`lC  
public class SiteInfoBean { muq|^Hfb  
@S:/6__  
nx]b\A  
private String sSiteURL; //Site's URL *<j@+Ch  
private String sFilePath; //Saved File's Path N!~NQ-Re'  
private String sFileName; //Saved File's Name aRP+?}b">  
private int nSplitter; //Count of Splited Downloading File hjT1SW\I  
9m9=O&C~-<  
mwhn=y#]*  
public SiteInfoBean() dz9-+C{m  
{//nSplitter的缺省值为5 <TuSU[]  
//default value of nSplitter is 5 ,p1]_D&  
this("","","",5); ml 2z  
} >Tx;<G  
PFw"ICs  
)5OU!c  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1dO8[5uM7a  
{ 4!qDG+m  
sSiteURL= sURL; qnRzs  
sFilePath = sPath; !r <|F  
sFileName = sName; Qq`\C0RZ  
this.nSplitter = nSpiltter; /)|y+<E]}  
,]"u!,yHb  
a~"X.xT\R  
} 0G 1o3[F  
~` hcgCi%  
K),wAZI!7j  
public String getSSiteURL() xxn&{\ ?  
{ g_X7@Dt  
return sSiteURL; h)`vc#"65k  
} `:4cb $  
AUV$ S2  
d(Ou\7  
public void setSSiteURL(String value) UQ~rVUo.c  
{ =h;!#ZC  
sSiteURL = value; Q(3x"+  
} z+I-3v  
b1o(CG(}*  
!Esiq<Yh  
public String getSFilePath() dY.uOafr  
{ KJfyh=AD(  
return sFilePath; Dw3! ibg  
} Oc`fQqYy  
B E)l77=/  
t_Wn<)XA  
public void setSFilePath(String value) o3kj7U:'x  
{ uNg.y$>CX  
sFilePath = value; #!Fs[A5%  
} [\yI<^_a  
d:''qgz`  
=1qkoc~  
public String getSFileName() [_-K  
{ AK =k@hT  
return sFileName; @=c='V]  
} Nb1lawC  
7 d5x4^EYE  
-y( V-  
public void setSFileName(String value) B=Os?'2[  
{ 0]~n8mB>  
sFileName = value; .Ps;O  
} XN;eehB?aE  
Yw<:I&  
0oMMJ6"i   
public int getNSplitter() '=@x2`U/  
{ !%@{S8IP.v  
return nSplitter; B!v1 gh  
} * ?+!(E  
WXL.D_=+  
!@X#{  
public void setNSplitter(int nCount) OUPpz_y  
{ ?`>yl4  
nSplitter = nCount; dp"w=~53  
} Me>'QVr  
} DI7trR`  
E \RU[  
< ]nI)W(  
/* 2srz) xEe  
**Utility.java 0^4*[?l9q  
*/ D4wB &~U  
package NetFox; 2H#vA  
/MC\ !,K  
tWFJx}H  
public class Utility { 4o8!p\a  
8] *{ i  
? 6l::M  
public Utility() :jPAA`,  
{ ajAEGD2Zq  
r.GjM#X  
wF(FV4#gs  
} lI 8"o>-~  
mx yT==E  
//线程睡眠 /Kvb$]F+!  
public static void sleep(int nSecond) Fk4 3sqU6~  
{ a lR}|ez  
try{ U#}.r<  
Thread.sleep(nSecond); 8z-Td-R6  
} 83a Rq&(R  
catch(Exception e) 9maw+c!~  
{ gyK"#-/_d  
e.printStackTrace (); K*<n<;W  
} M: 6 cma5  
} L!Ro`6|7;  
D-.>Dw:  
//日志 O\w%E@9Fh  
public static void log(String sMsg) (LjY<dQO  
{ UgP5^3F2  
System.err.println(sMsg); /d4xHt5a  
} P<hqr;  
-~q]0>  
o\#C] pp  
public static void log(int sMsg) ) l)5^7=W  
{  P/Z o  
System.err.println(sMsg); 6 D O E6  
} 9pgct6BO  
} 0[];c$r<  
uFqH_04  
BSz\9 eT  
/* e.T5F`Du  
**TestMethod.java ZDf9Npe  
*/ wmIq{CXx,  
package NetFox; + |,CIl+  
,y.0 Cb0  
vcmS]$}  
public class TestMethod { b6lL8KOu  
sDiYm}W  
.UcS4JU  
public TestMethod() <3qbgn>}b  
{ ///xx/weblogic60b2_win.exe ^\!p ;R  
try{ e:l 6;  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R3~&|>7/T  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (F)zj<{f  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ivm.ng[  
fileFetch.start(); A9#2.5  
} t*x;{{jL#(  
catch(Exception e){e.printStackTrace ();} %(E6ADB  
+[F8>9o&  
s{/nO)  
} QWoEo  
L*Y}pO  
=[WccF  
public static void main(String[] args) gUMUh] j  
{ _,}Ye,(^=  
new TestMethod(); _i 8oWy1  
} \rJk[Kec  
} ZjcJYtD  
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