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http断点续传简单实现(java)

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/*  Qxz[  
**SiteFileFetch.java s!(R  
*/ L3{(B u  
package NetFox; 2Wzx1_D "a  
import java.io.*; pyhXET '  
import java.net.*; tz):$1X_  
$0[T<]{/?  
C&z!="hMhR  
public class SiteFileFetch extends Thread { "L2*RX.R  
OD)X7PU  
T ipH}  
SiteInfoBean siteInfoBean = null; //文件信息Bean S1$^ _S =  
long[] nStartPos; //开始位置 +@ChZ  
long[] nEndPos; //结束位置 %"`p&aE:  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 t2,II\K l  
long nFileLength; //文件长度 xJ3C^b%H  
boolean bFirst = true; //是否第一次取文件 FQ>$Ps*a[  
boolean bStop = false; //停止标志 B_d\eD  
File tmpFile; //文件下载的临时信息 t/[lA=0 )2  
DataOutputStream output; //输出到文件的输出流 yv-R<c!'  
k'iiRRM  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) J2qsZ  
public SiteFileFetch(SiteInfoBean bean) throws IOException (1z"=NCp  
{ ]({ -vG\m  
siteInfoBean = bean; ExG(*[l  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); |:S6Gp[\O  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 2}&ERW  
if(tmpFile.exists ()) IRbyW?/Xv  
{ GDLi ?3q  
bFirst = false; ^(JrOh'  
read_nPos(); =n,;S W  
} R%.`h  
else U =J5lo  
{ {L;sF=d  
nStartPos = new long[bean.getNSplitter()]; ;VLDXvGd  
nEndPos = new long[bean.getNSplitter()]; ^/#+0/Bn  
} 5[;[Te9=S  
e_b,{l#  
Ii+3yE@c  
w Q[|D2;  
} "5N4 of 8  
~IZ-:?+S^  
=%|`gZ  
public void run() ^ =C>  
{ O::FB.k  
//获得文件长度  J#` 7!  
//分割文件 Vq3NjN!+5  
//实例FileSplitterFetch <.)=CK  
//启动FileSplitterFetch线程 c';~bYZ  
//等待子线程返回 Fu.aV876\f  
try{ =>'8<"M5z  
if(bFirst) `sm Cfh}j6  
{ ]\yB,  
nFileLength = getFileSize(); THwM',6  
if(nFileLength == -1) CzV;{[?~;  
{ cx:_5GF  
System.err.println("File Length is not known!"); [h-6;.e  
} XKGiw 2 C  
else if(nFileLength == -2) i6paNHi*  
{ [<=RsD_q~  
System.err.println("File is not access!"); F/2cQ .u2  
} tz]0F5  
else r $S9/  
{ @_`r*Tb)dM  
for(int i=0;i<nStartPos.length;i++) "[ LUv5  
{ g/C 7wc  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); <lB2Nv-,  
} %uo8z~+  
for(int i=0;i<nEndPos.length-1;i++) j#f/M3  
{ OmuE l>  
nEndPos = nStartPos[i+1]; )?[2Y%P  
} "1s ]74  
nEndPos[nEndPos.length-1] = nFileLength; )FwOg;=3M"  
} 9we];RYK  
} w}1IP-  
<l1/lm<#  
`:lcN0n  
//启动子线程 7Q/H+)  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mywx V  
for(int i=0;i<nStartPos.length;i++) k$v 7@|Aw  
{ Qb@j8Xa4[  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1le9YL1_g  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZTTA??}Y  
nStartPos,nEndPos,i); q-t%spkl  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eSoX|2g  
fileSplitterFetch.start(); vE9"1M  
} b#I,Z+0ry  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '\{ OQ H  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6Y[&1c8  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s>;"bzzq  
nEndPos = " + nFileLength); oRd{?I&NY  
// fileSplitterFetch[nPos.length-1].start(); <vl(a*4a  
)[hs#nKTh  
^(&2  
//等待子线程结束 ^RnQX#+  
//int count = 0; Y<;C>Rs  
//是否结束while循环 ]/ !*^;cY(  
boolean breakWhile = false; Q+f |.0r  
!}c D e12  
HV!P]82Pa  
while(!bStop) Jha*BaD~N  
{ %;4#?.W8  
write_nPos(); _3 [E$Lg  
Utility.sleep(500); wSjy31  
breakWhile = true; 3wN4kltt  
t>]W+Lx#  
0(&uH0x  
for(int i=0;i<nStartPos.length;i++) 5M\0t\uEn  
{ Mxz X@GBX  
if(!fileSplitterFetch.bDownOver) 4oF,;o+v\4  
{ 36'J9h\  
breakWhile = false; rKPsv*w  
break; 2;]tItd1  
} lJa-O  
} toF6 Z  
if(breakWhile) 'NWvQR<X  
break; BfCib]V9C  
AkjoD7.*  
h1>.w pr  
//count++; p,WBF  
//if(count>4) Rt%Dps%  
// siteStop(); f~d =1  
} .~'q yD2V  
Ge$&k  
NO*~C',cI/  
System.err.println("文件下载结束!"); _)-2h[  
} &\?{%xj  
catch(Exception e){e.printStackTrace ();} N cHCcc  
} J'cE@(US  
5YZ\@<|rH  
@W+8z#xr'  
//获得文件长度 21$^k5  
public long getFileSize() w;VUP@Wm  
{ m";8 nm  
int nFileLength = -1; "~C \Z} ;  
try{ |RpZr!3V  
URL url = new URL(siteInfoBean.getSSiteURL()); qyyLU@hd  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ahd{f!  
httpConnection.setRequestProperty("User-Agent","NetFox"); M]\"]H?  
oQyMs>g  
&m(eMX0lU  
int responseCode=httpConnection.getResponseCode(); 5NSXSR9c  
if(responseCode>=400) Rpcnpo  
{ 2b {Y1*  
processErrorCode(responseCode); 'H1"z!]  
return -2; //-2 represent access is error + $~HRbo  
} AO$aWyI  
P\c0Q;){h"  
(I`< ;  
String sHeader; hy"p8j7_  
LY0/\Z"N  
etW-gbr  
for(int i=1;;i++) I |D]NY^  
{ a(o[ bH.|;  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); iEFS>kL8e  
//Utility.log(in.readLine()); n O}x,sG2'  
sHeader=httpConnection.getHeaderFieldKey(i); jM@@N.  
if(sHeader!=null) AM gvk`<f  
{ 43J8PMY  
if(sHeader.equals("Content-Length")) }=3W(1cu-  
{ p|Fhh\,*`X  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]*S_fme  
break; uuh vd h=  
} 1_W5@)  
} Qe/=(P<  
else Hi{!<e2  
break; L3Q1az!Ct  
} _Q;M$.[zyR  
} I(WND/&  
catch(IOException e){e.printStackTrace ();} $PbN=@  
catch(Exception e){e.printStackTrace ();} Y@'1}=`J  
#iGz&S3iN$  
P3XP=G`E  
Utility.log(nFileLength); NOmSLIgt7  
j1toV$)P  
1/q iE{NW  
return nFileLength; y+iuA@WCv  
} 0H.B>: pv  
kqAQrg]n  
&sA6o"h~  
//保存下载信息(文件指针位置) ~pSD|WX  
private void write_nPos() o:Z*F0qm  
{ .J\U|r  
try{ >-y&k^a=  
output = new DataOutputStream(new FileOutputStream(tmpFile)); El&pu x2  
output.writeInt(nStartPos.length); A[':O*iB  
for(int i=0;i<nStartPos.length;i++) &<i>)Ss  
{ U7fE6&g  
// output.writeLong(nPos); l 0b=;^6  
output.writeLong(fileSplitterFetch.nStartPos); >|I3h5\M  
output.writeLong(fileSplitterFetch.nEndPos); ;/{Q4X{  
} 4_I,wG@  
output.close(); &(^>}&XS.<  
} "Lpt@g[HF  
catch(IOException e){e.printStackTrace ();} m~NWY$oI9[  
catch(Exception e){e.printStackTrace ();}  Ez1*}  
} <u($!ATb  
9'8oOBqm3%  
$X&OGTlw^  
//读取保存的下载信息(文件指针位置) E.% F/mM  
private void read_nPos() 2Nl("e^kJr  
{ C1rCKKh  
try{ d`nS0Tf'  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r@<;  
int nCount = input.readInt(); +#H8d1^5  
nStartPos = new long[nCount]; B 9Mwj:)}  
nEndPos = new long[nCount]; 3S2'JOTY  
for(int i=0;i<nStartPos.length;i++) i+cGw  
{ o-' i)pp  
nStartPos = input.readLong(); /~tfP  
nEndPos = input.readLong(); 6k3l/~R  
} ;<X3AhF  
input.close(); '}YXpB  
} x?<5=,  
catch(IOException e){e.printStackTrace ();} a@r K%Iff  
catch(Exception e){e.printStackTrace ();} D3lYy>~d5;  
} 'IW+"o  
kWz%v  
>`\*{]  
private void processErrorCode(int nErrorCode) Y@\5gZ&T  
{ =,]J"n8|v  
System.err.println("Error Code : " + nErrorCode); ft6^s(t  
} A0X0t  
#"yf^*wX  
7ER 2 h*  
//停止文件下载 ?Ru`ma\;  
public void siteStop() I2DmM"-|  
{ aQmL=9  
bStop = true; d=KOV;~);  
for(int i=0;i<nStartPos.length;i++) \j;uN#)28  
fileSplitterFetch.splitterStop(); CGe'z  
p+7BsW.l  
!^fJAtCN]  
} \mu9ikZ<  
} XP^6*}H.*  
//负责部分文件的抓取 7~Ga>BK  
**FileSplitterFetch.java 1=a}{)0h  
*/ TxCQGzqe  
package NetFox; k"7eHSy,  
` U3  
G\p; bUF  
import java.io.*; rlIEch^wZ  
import java.net.*; t3>r f3v  
YPy))>Q>cK  
hw'2q9J|  
public class FileSplitterFetch extends Thread { S7q &|nI  
"qm>z@K  
">QY'r  
String sURL; //File URL uWInx6p  
long nStartPos; //File Snippet Start Position .nH /=  
long nEndPos; //File Snippet End Position kZ.3\  
int nThreadID; //Thread's ID 66Xt=US  
boolean bDownOver = false; //Downing is over *&0Hz{|  
boolean bStop = false; //Stop identical 9|WWA%p  
FileAccessI fileAccessI = null; //File Access interface ?^vZ{B)&0E  
J| '(;Ay4u  
yrs3`/  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X[~CLKH(  
{ LG|,g3&  
this.sURL = sURL; LI<5;oE;  
this.nStartPos = nStart; ;MJ1Q  
this.nEndPos = nEnd; JAz;_wS(k  
nThreadID = id; ZO 1J";>u  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5l}h8So4  
} Zn0fgQd  
g\)z!DQ]  
qi2dTB  
public void run() iP%=Wo.  
{ F]*-i 55S  
while(nStartPos < nEndPos && !bStop) 7&)F;;H  
{ R*0F)M  
6v#G'M#r  
!v L :P2  
try{ W 8NA.  
URL url = new URL(sURL); iIw ea`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i?/?{p$#a-  
httpConnection.setRequestProperty("User-Agent","NetFox"); $bosGG  
String sProperty = "bytes="+nStartPos+"-"; ~&:R\  
httpConnection.setRequestProperty("RANGE",sProperty); ECzNByP  
Utility.log(sProperty); \(FDR  
_64@zdL+  
-JENY|6  
InputStream input = httpConnection.getInputStream(); mD)O\.uA  
//logResponseHead(httpConnection); @GtZK  
vNSf:5H$  
TMCA?r%Y\  
byte[] b = new byte[1024]; RWo B7{G  
int nRead; !S-U8KI|  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [ d7]&i}*|  
{ <pUou  
nStartPos += fileAccessI.write(b,0,nRead); c7IR06E  
//if(nThreadID == 1) |u;PU`^-z  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ItPK  
} 3= zQ U  
*KH@u  
eBIR *TZ):  
Utility.log("Thread " + nThreadID + " is over!"); r_E)HL/A  
bDownOver = true; U.'@S8  
//nPos = fileAccessI.write (b,0,nRead); 8Jj0-4]  
} 3]es$Jy  
catch(Exception e){e.printStackTrace ();} ]?`p_G3O  
} x 4</\o  
} F5MPy[  
9lJj/  
[B @j@&  
//打印回应的头信息 u g"<\"  
public void logResponseHead(HttpURLConnection con) H;|:r[d!  
{ |uBC0f  
for(int i=1;;i++) 3og$'#6P  
{ H`lD@q'S  
String header=con.getHeaderFieldKey(i); "@w%TcA  
if(header!=null) E}9ldM=]s  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ](:FW '-  
Utility.log(header+" : "+con.getHeaderField(header)); c|( ?  
else =>\-ma+  
break; /+`<X%^U  
} {taVAcb  
} L_K\i?  
_C,@eu"9V  
f\U&M,L\ '  
public void splitterStop() @[lc0_ b  
{ oImgj4C2L  
bStop = true; AWXpA1(  
} ?lN8~Ze  
M2Fj)w2   
M.N~fSJ   
} wKS-O%?  
gam#6 s  
%`1CE\f  
/* 2 RUR=%C  
**FileAccess.java EvQwGt1)P  
*//文件访问(定位,写) ZNpExfGEU  
package NetFox; yPh2P5}H>  
import java.io.*; Ca@=s  
QsJW"4d  
bH&)rn  
public class FileAccessI implements Serializable{ bTQa'y`3  
g+ 1=5g  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /:{_|P\  
RandomAccessFile oSavedFile; D>b5Uwt  
long nPos; <-B"|u  
]Bd3d%  
|EV\a[  
public FileAccessI() throws IOException !FO^:V<|5  
{ #lshN,CPm  
this("",0); 6mpg&'>  
} pNE\@U|4E  
@ PoFxv  
fCf#zV[  
public FileAccessI(String sName,long nPos) throws IOException K}E7|gdG  
{ h<' 5q&y  
oSavedFile = new RandomAccessFile(sName,"rw"); Oqpl2Y"/  
this.nPos = nPos; -jtC>_/  
oSavedFile.seek(nPos); u@_!mjXQ  
} t_>bTcsU  
dEd]U49u  
~@uY?jr  
public synchronized int write(byte[] b,int nStart,int nLen) TF0-?vBWh  
{ hdr}!w V  
int n = -1; JV]u(PL  
try{ IgVo%)n  
oSavedFile.write(b,nStart,nLen); [}ZPg3Y  
n = nLen; G</I%qM  
} v V6Lp  
catch(IOException e) SU%rWH  
{ (21 W6  
e.printStackTrace (); tdnXPxn[  
} 2iPmCG  
$rpTs?j*K$  
]r6BLZ[%  
return n; leES YSY:  
} ke9QT#~p!-  
Fb|e]?w  
:x""E5H  
} &H4uvJ_<  
V(2j*2R!  
_@/C~  
/* _h1 HuL  
**SiteInfoBean.java MO~~=]Y'  
*/ ..]*Ao2  
package NetFox; +eBMn(7Cgv  
A!ioji+{[  
{;iH Yr-zs  
public class SiteInfoBean { /}nrF4S  
tSb?]J  
uqa4&2(I=j  
private String sSiteURL; //Site's URL UROj9CO v  
private String sFilePath; //Saved File's Path ?H[5O+P[  
private String sFileName; //Saved File's Name 8{G?92 {rN  
private int nSplitter; //Count of Splited Downloading File  t$H':l0  
pdi=6<?bd  
6/[Z178m  
public SiteInfoBean() ^5;vx  
{//nSplitter的缺省值为5 T1(j l)  
//default value of nSplitter is 5 &8]#RQy{f  
this("","","",5); UEEBWzH  
} 7bonOt Y  
X%a;i6pq  
b$?Xn{Y  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .lvI8Jf~X  
{ uS,p|}Q&  
sSiteURL= sURL; rmPne8D=c(  
sFilePath = sPath; lk[G;=K:.  
sFileName = sName; B0)`wsb_  
this.nSplitter = nSpiltter; 8 _4l"v p  
oI_oz0nHk  
-v;n"Zy1  
} F<yy>Wf  
q}<.x8\  
1iNsX\M  
public String getSSiteURL() oNuPP5d[]  
{ \6SMn6a4  
return sSiteURL; PG6[lHmi  
} X(GmiH /E  
C#Hcv*D  
~5r=FF6  
public void setSSiteURL(String value) I(OAEIz  
{ <H5n>3#pH  
sSiteURL = value; aFRTNu/r  
} 9Qzjqq:"Li  
y Y>-MoF/t  
mW~i c  
public String getSFilePath() u/gm10<OWa  
{ zBk_-'z  
return sFilePath; _m9~*  
} b:P\=k]8#  
 2Vp>"  
X,RT<GNNb  
public void setSFilePath(String value) (TEo_BW|+  
{ 87^:<\pp  
sFilePath = value; \npz .g^c_  
} W\it+/  
!}>eo2$r^  
F2IC$:e M  
public String getSFileName() 8yE!7$Mj  
{ l60ikc4$I  
return sFileName; g!1I21M1~  
} Mn]}s:v  
G*i.a*9<)  
?SC3Vzr  
public void setSFileName(String value) uu}a:qrY  
{ 1P_Fe[8  
sFileName = value;  5ZnSA9?  
} O6yP qG*j  
$d'CBsu|<  
{]&R8?%  
public int getNSplitter() JAc@S20v\  
{ .Qd}.EG  
return nSplitter; 1^aykrnQ>  
} p{NPcT%&  
^DBD63 N"  
L~*u4  
public void setNSplitter(int nCount) L)q`D2|'  
{ W|;nJs:e  
nSplitter = nCount; o g_Ri$x8  
} 6 |QTS|!  
} Js/N()X  
BSN6|W  
aT&t_^[]   
/* GF&_~48GD  
**Utility.java XmP;L(wa   
*/ avlqDi1l  
package NetFox; I$n+DwKcN  
^>-+@+( r  
i wUv`>l&  
public class Utility { PmHd9^C  
]de\i=?|  
Ujf,6=M  
public Utility() /K f L+"^|  
{ iBucT"d]  
5i6VZv  
T-^0:@5o9  
} sr\cVv")  
UanEzx%  
//线程睡眠 W/sY#"  
public static void sleep(int nSecond) RF:04d  
{ @9aGz6k+  
try{ h{I`7X  
Thread.sleep(nSecond); gt'*B5F(  
} 47KNT7C  
catch(Exception e) 8+ov(B;(  
{ GSP?X$E  
e.printStackTrace (); YNI;h%w  
} yx2z%E  
} YV-j/U{&  
1DUb [W8  
//日志 a~,Kz\Tt  
public static void log(String sMsg) F'1k<V?  
{ sMP:sCRC  
System.err.println(sMsg); #00D?nC  
} ^ESUMXb  
`g--QR  
R }1W  
public static void log(int sMsg) . @@an;C  
{ $%Z3;:<Uf-  
System.err.println(sMsg); *#zS^b n  
} m~;B:LN<  
} CI^[I\$&  
\0nlPXk?G  
h(nj,X+  
/* >zQOK-  
**TestMethod.java 88+ =F XG  
*/ =5?.'XMk  
package NetFox; `%Q&</X  
wqP2Gw7jh6  
> VP5vkv=  
public class TestMethod { b:1 L@8s;  
/[%w*v*'  
okstY4f'  
public TestMethod() p-xd k|'[  
{ ///xx/weblogic60b2_win.exe D^|9/qm$  
try{ w//omF'`  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .%IslLZ  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g8RPHjvZ  
SiteFileFetch fileFetch = new SiteFileFetch(bean); W!91tzs:  
fileFetch.start(); /D'M24  
} ?_%u)S*g  
catch(Exception e){e.printStackTrace ();} ya.n'X14  
xz8G}Ku  
FIS "Z(  
} {rDq_^  
JGis"e  
s9i|mVtm8  
public static void main(String[] args) q*bt4,D&Es  
{ tb,9a!?  
new TestMethod(); P\AqpQv  
} t+O e)Ns  
} ,:UX<6l R  
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