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http断点续传简单实现(java)

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/* 68 % = V>V  
**SiteFileFetch.java 0|kkwZVPn  
*/ =e2|:Ba!  
package NetFox; v#1}( hb  
import java.io.*; 4RCD<7  
import java.net.*; I8;xuutc  
p|!5G&O,  
~.99H  
public class SiteFileFetch extends Thread { `yYoVu*  
F?#^wm5TZ  
LT7C>b  
SiteInfoBean siteInfoBean = null; //文件信息Bean P;_}nbB  
long[] nStartPos; //开始位置 l"70|~  
long[] nEndPos; //结束位置 U$+EUDFi3_  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Lc.=CBQ  
long nFileLength; //文件长度 a*?bnw?  
boolean bFirst = true; //是否第一次取文件 +XV7W=  
boolean bStop = false; //停止标志 KY5it9e  
File tmpFile; //文件下载的临时信息 /J''`Tf  
DataOutputStream output; //输出到文件的输出流 jc rLUs+\  
4&b*|"Iw  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) @r7ekyO8)  
public SiteFileFetch(SiteInfoBean bean) throws IOException cP#vzFB0>  
{ H_w&_h&  
siteInfoBean = bean; gR7in!8  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 1dDK(RBbQ  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); .g/PWEr\I  
if(tmpFile.exists ()) r<< ]41  
{ HRQ3v`P.  
bFirst = false; P/%5J3_,  
read_nPos();  zciL'9  
} #aHPB#  
else @8\7H'K"\  
{ 4FwtC"G3  
nStartPos = new long[bean.getNSplitter()]; qPal'c0  
nEndPos = new long[bean.getNSplitter()]; `Hlv*" w$  
} KZeaM  
CuT~ Bj  
N{b ;kiZq  
olA 1,8  
} LDX>S*cL  
fHFy5j0H  
Dx1f< A1  
public void run() Gl am(V1  
{ 6KH&-ffd  
//获得文件长度 z5njblUz  
//分割文件 ^9_4#Ep(  
//实例FileSplitterFetch _;z IH5 H  
//启动FileSplitterFetch线程 $3yzB9\a"  
//等待子线程返回 YRU1^=v  
try{ 5xb1FH d:  
if(bFirst) D MzDV_  
{ ,ma4bqRMc  
nFileLength = getFileSize(); OYYk[r  
if(nFileLength == -1) QV%,s!_b  
{ xZE%Gf_U  
System.err.println("File Length is not known!"); ]=ubl!0=:  
} 5w9oMM {  
else if(nFileLength == -2) +.3,(l  
{ ?xTdL738  
System.err.println("File is not access!"); |'+ [ '  
} d,V]j-  
else paYvYK-K?  
{ _~}n(?>  
for(int i=0;i<nStartPos.length;i++) (~U1 X4  
{ 7eU|iDYo  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ZHN}:W/p  
} L"x9O'U  
for(int i=0;i<nEndPos.length-1;i++) 9{- Sa  
{ ^Mc zumG[  
nEndPos = nStartPos[i+1]; KQu lz  
} 7dh--.i  
nEndPos[nEndPos.length-1] = nFileLength; 5^0K5R6GQf  
} }uo.N  
} XEpwk,8*g  
%YLyh?J  
gI5Fzk@:  
//启动子线程 ~i5t1  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |]=s  
for(int i=0;i<nStartPos.length;i++) z$]HZ#aRE  
{ 6>e YG <y{  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y&(R1Y75  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mA" 82"   
nStartPos,nEndPos,i); Op 0Qpn  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F7N4qq1  
fileSplitterFetch.start(); k 1sR^&{l  
} xA#'%|"  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UEh-k"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ];7/DM#Np  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \EC7*a0  
nEndPos = " + nFileLength); $?Yw{%W  
// fileSplitterFetch[nPos.length-1].start(); g| M@/D l  
EwuBL6kN  
O ]Stf7]%;  
//等待子线程结束 >G<.^~o  
//int count = 0; jPyhn8Vw  
//是否结束while循环 vkg."G:=  
boolean breakWhile = false; 6JZ$; x{j  
(.J8Q  
(U@uJ  
while(!bStop) rxM)SC;P  
{ r<XlIi  
write_nPos(); -_xC,dwK  
Utility.sleep(500); Jz Z9ua  
breakWhile = true; |@lVFEl]  
x}*Y =Xh  
^{(i;IVG  
for(int i=0;i<nStartPos.length;i++) @ZFU< e$!  
{ )9mUE*[  
if(!fileSplitterFetch.bDownOver) %m0x]  
{ C~([aH@-I  
breakWhile = false; mzoNXf:x  
break; H,5 ##@X  
} K-f\nr  
} z6 A`/ jF}  
if(breakWhile) $v*0 \O  
break; M~ ^ {S[o  
D|BP]j}6  
_Sxp|{H0  
//count++; 2xJT!lN  
//if(count>4) 0-{l4;o  
// siteStop(); {Vj25Gt  
} A1u|L^  
I-`qo7dQ_S  
qf qp}g\  
System.err.println("文件下载结束!"); dS[="Set  
} `+go| 5N2  
catch(Exception e){e.printStackTrace ();} -$J%.fdPs  
} T1}9^3T?{  
N;BS;W5I  
_Mis-K:]{?  
//获得文件长度 e2xqK G  
public long getFileSize() UIl^s8/  
{ b2vc  
int nFileLength = -1; LN?b6s75U  
try{ At#'q>Dn  
URL url = new URL(siteInfoBean.getSSiteURL()); koizk&)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )5M9Ro7  
httpConnection.setRequestProperty("User-Agent","NetFox"); VN1a\  
ecI[lB  
BkTGH.4G%  
int responseCode=httpConnection.getResponseCode(); aF'9&A;q  
if(responseCode>=400) pdrF/U+  
{ # Y*cLN`Y7  
processErrorCode(responseCode); F ;m1I+;  
return -2; //-2 represent access is error "w\Iz]  
} q;kN+NK64  
|5}~n"R5  
wPl!}HNf  
String sHeader; ]v^;]0vcr  
vkXdKL(q  
F;IG@ &  
for(int i=1;;i++) L|3wG Y9E  
{ 5[Ryc[  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n+EK}= DK  
//Utility.log(in.readLine()); g8{?;  
sHeader=httpConnection.getHeaderFieldKey(i); Ass8c]H@  
if(sHeader!=null) @lau?@$ja  
{ gJy Ft8Z<  
if(sHeader.equals("Content-Length")) $UZ4,S?V  
{ "$Wi SR  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cs?@Ri=g  
break; &B^vHH  
} vYD>m~Qc^  
} 1 D fB9n  
else *mM+(]8US  
break; }[u9vZL  
} eXaa'bTx  
} m<BL/ 7  
catch(IOException e){e.printStackTrace ();} dm Lgt)-t  
catch(Exception e){e.printStackTrace ();}  {Y9m;b,X  
,~Y5vnaOQ  
xw5E!]~D  
Utility.log(nFileLength); DlR&Lnv  
#;RP ?s  
$J #}3;a  
return nFileLength; icF -`m  
} yKO84cSl  
a$MMp=p  
UcMe("U  
//保存下载信息(文件指针位置) i&^?p|eKa  
private void write_nPos() HnVUG4yZTD  
{ `5`Pv'`  
try{ #](k,% 2  
output = new DataOutputStream(new FileOutputStream(tmpFile)); n>\BPiz  
output.writeInt(nStartPos.length); ^sq3@*hCw  
for(int i=0;i<nStartPos.length;i++) "w`f>]YLA  
{ sHe:h XG'  
// output.writeLong(nPos); =MG  
output.writeLong(fileSplitterFetch.nStartPos); yov:JnWo  
output.writeLong(fileSplitterFetch.nEndPos); _f,q8ZkSr  
} .9 WUp>  
output.close(); c?d+>5"VX  
} Y ,?  
catch(IOException e){e.printStackTrace ();} -,96Qg4vI  
catch(Exception e){e.printStackTrace ();} amGQ!$] %#  
} BoP%f '0N  
N7Z&_$Bx  
T}2a~  
//读取保存的下载信息(文件指针位置) -nO('(t  
private void read_nPos() x}1(okc  
{ "twV3R  
try{ ]xf{.z  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Z8k O*LYv  
int nCount = input.readInt(); W #qM$  
nStartPos = new long[nCount]; 5Zn3s()  
nEndPos = new long[nCount]; F& H~JJ  
for(int i=0;i<nStartPos.length;i++) _Ux>BJmP  
{ >S{1=N@Ev=  
nStartPos = input.readLong(); ^k^%w/fo  
nEndPos = input.readLong(); U*k$pp6\b~  
} d[rxmEXht  
input.close(); )sB`!:~HjP  
} [fR<#1Z  
catch(IOException e){e.printStackTrace ();} jzEimKDE's  
catch(Exception e){e.printStackTrace ();} 5.VA1  
} ~AK!_EOs`  
h+.^8fPR   
l},px  
private void processErrorCode(int nErrorCode) :":W(O  
{ ,X\z#B  
System.err.println("Error Code : " + nErrorCode); 5yxZ 5Ni!  
} zK:/ 1  
":"M/v%F  
QE)g==d  
//停止文件下载 'L3 \I  
public void siteStop() |}q0 G~l  
{ Os@ofnC  
bStop = true; S~/iH Xm  
for(int i=0;i<nStartPos.length;i++) W .Hv2r3  
fileSplitterFetch.splitterStop(); p$[*GXR4  
"VcGr#zW  
_vU,avw  
} 348Bu7':  
} 1oX"}YY1  
//负责部分文件的抓取 30<dEoF  
**FileSplitterFetch.java {,s:vPoiA  
*/ r*+9<8-ZX<  
package NetFox; R"O9~s6N  
KD Qux  
S~Q7>oNm  
import java.io.*; KM0#M'dXy  
import java.net.*; >t*zY~R.  
3\mFK$#sr  
Nob(bD5SpE  
public class FileSplitterFetch extends Thread { _FdWV?  
k,?Y`s  
}E/L:  
String sURL; //File URL N.-Ryj&9  
long nStartPos; //File Snippet Start Position )-jvp8%BK  
long nEndPos; //File Snippet End Position &|{K*pNa  
int nThreadID; //Thread's ID kN]#;R6  
boolean bDownOver = false; //Downing is over B0 R[f  
boolean bStop = false; //Stop identical }JlQQ  
FileAccessI fileAccessI = null; //File Access interface Rut6m5>  
{v`wQM[  
SxH}/I|W  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F=P|vYL&&  
{ %eT/:I  
this.sURL = sURL; dOiy[4s  
this.nStartPos = nStart; #4c uNX5m%  
this.nEndPos = nEnd; Yhlk#>I  
nThreadID = id; #d|.BxH  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >nr1|2  
} Kw?,A   
0q`'65 lx  
MESQAsx%  
public void run() &12aI |u^<  
{ ' GW@P  
while(nStartPos < nEndPos && !bStop) %%k[TO  
{ ?$s2] }v  
*i$+i  
T+.wJ W:jh  
try{ BO[A1'>  
URL url = new URL(sURL); <XLATS8Y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !8A5Y[(XD  
httpConnection.setRequestProperty("User-Agent","NetFox"); =_,OucKkYG  
String sProperty = "bytes="+nStartPos+"-"; ;hZ(20  
httpConnection.setRequestProperty("RANGE",sProperty); T%]: tDa  
Utility.log(sProperty); *aT!|;  
c2F`S1Nu<  
.#Sd|C]R7  
InputStream input = httpConnection.getInputStream(); oNEU?+  
//logResponseHead(httpConnection); t(_XB|AKm  
mV4} -  
z&t6,0q`5  
byte[] b = new byte[1024]; 9g*~X;`2  
int nRead; S%T1na^x  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U>I#f  
{ -pjL7/gx  
nStartPos += fileAccessI.write(b,0,nRead); O42An$}  
//if(nThreadID == 1) :8 )4:4$^  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j1d=$'a "  
} v~xG*e  
C<7J5  
Cy2X>Tl"<E  
Utility.log("Thread " + nThreadID + " is over!"); +_ G'FD  
bDownOver = true; :?^(&3;  
//nPos = fileAccessI.write (b,0,nRead); >l7 o/*4  
} J$P]>By5:  
catch(Exception e){e.printStackTrace ();} nh8h?&q|  
} xGH%4J\  
} TfxKvol'  
q6DhypB  
]pGr'T~Gj  
//打印回应的头信息 !#?tA/t@  
public void logResponseHead(HttpURLConnection con) {C6Yr9  
{ u9&p/qMx2  
for(int i=1;;i++) $i2gOz  
{ C1nQZtF R  
String header=con.getHeaderFieldKey(i); Vw#07P#A  
if(header!=null) )a6i8b3  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A} "*`y  
Utility.log(header+" : "+con.getHeaderField(header)); F 4h EfO3  
else ,L^L uw'7  
break; [v&_MQ  
} M6I1`Lpf  
} J|b1 K]  
2V0R|YUt  
:I7MP   
public void splitterStop() mB :lp=c`  
{ uu/M XID  
bStop = true; 1,mf]7k$  
} 5N6%N1  
L%<1C \k  
 {jl4`  
} 7+fik0F  
Vz,WPm$I  
5_O.p3$tV  
/* M-Js"cB[  
**FileAccess.java *rbH|o8  
*//文件访问(定位,写) Gmwn:  
package NetFox;  O{4m-;  
import java.io.*; _Nj;Ni2rD  
JDs<1@\  
dYsqF 3f  
public class FileAccessI implements Serializable{ '"TBhisky  
ALG #)$|  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |fA[s7)  
RandomAccessFile oSavedFile; #Q{6/{bM&J  
long nPos; `K@   
kz&)a>aA  
RsY<j& f  
public FileAccessI() throws IOException *0iP*j/]  
{ ]juXm1)>W1  
this("",0); mkWIJH  
} ecF I"g  
}C'z$i( y  
h{! @^Q  
public FileAccessI(String sName,long nPos) throws IOException o1Xk\R{  
{ *=I#VN*_<.  
oSavedFile = new RandomAccessFile(sName,"rw"); tSm|U<  
this.nPos = nPos; ?T^$,1 -  
oSavedFile.seek(nPos); !98s[)B:  
} "qF&%&#r'  
Q`oi=O YB  
(zhmZm  
public synchronized int write(byte[] b,int nStart,int nLen) NLdUe32A  
{ )sL:iGU  
int n = -1; 9+/<[w7  
try{ >Z3}WMgBN  
oSavedFile.write(b,nStart,nLen); a@ lK+t  
n = nLen; `$i`i'S  
} $$8"i+,K  
catch(IOException e) ~@-Az([H  
{ pymT-  
e.printStackTrace (); ?>,aq>2O$  
} UA/3lH}  
[A3hrSw  
qH-dT,`"{  
return n; v/^2K,[0>  
} ou(9Qf zN  
b\^.5SEw  
|mK d5[$  
} P#yS]F/  
dJ|]W|q<  
@z2RMEC~  
/* 0nl)0|?Az  
**SiteInfoBean.java ./6L&?*`~;  
*/ {g);HnmPN  
package NetFox; o30PI  
W9u (  
ad"&c*m[  
public class SiteInfoBean { GWhb@K  
bg$e80  
8RocObY_W  
private String sSiteURL; //Site's URL N.VzA 6 C  
private String sFilePath; //Saved File's Path )ei+ewVZ  
private String sFileName; //Saved File's Name PvA%c<z  
private int nSplitter; //Count of Splited Downloading File mp5]=6 ~:m  
]`|bf2*eA  
pZWp2hj{X  
public SiteInfoBean() ."H5.'  
{//nSplitter的缺省值为5 gHm ^@  
//default value of nSplitter is 5 HFf| >&c&  
this("","","",5); m=n V$H   
} jm*v0kNy  
 D}_\oE/n  
M r@M~ -  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8HWY]:| oh  
{ "#p)Z{v"!  
sSiteURL= sURL; EKDv3aFQZ#  
sFilePath = sPath; |_ ;-~bmb  
sFileName = sName; [y:6vC   
this.nSplitter = nSpiltter; u2F 3>s  
GHoPv-#  
6%5A&&O(b  
} 9aXm}  
.2u%;)S  
LtNG<n)_BH  
public String getSSiteURL() gzuM>lf*{  
{ m2 OP=z@)  
return sSiteURL; JM M\  
} AA@J~qd u  
%5uuB4P&|$  
MenI>gd?  
public void setSSiteURL(String value) O[-wm;_(=*  
{ 8^HMK$  
sSiteURL = value; 2sf/^XC1  
} c !5OK4+Z  
id*UTY Tg  
[]u!piW  
public String getSFilePath() 8XTVpf4  
{ J4x1qY)Y&v  
return sFilePath; :yw0-]/DD  
} $3FFb#r  
;B tRDKn  
}z[ O_S,X  
public void setSFilePath(String value) rYc?y  
{ /LJ?JwAvg5  
sFilePath = value; bk"` hq  
} -BB5bsjA  
JSO>rpO  
rs!J<CRq  
public String getSFileName() - 5A"TNU  
{ |~'{ [?a*  
return sFileName; \ar.(J  
} koaH31Q  
ZfMJU  
XD*$$`+#  
public void setSFileName(String value) B9+oI c O  
{ P 0,]Ud  
sFileName = value; 9B<y w.  
} kigc+R  
qk<tLvD_'  
Th@L68  
public int getNSplitter() yzXwxi1#  
{ l=kgRh  
return nSplitter; jz/@Zg",  
} O^ f[ ugs  
`qX'9e3VP+  
BEu9gu  
public void setNSplitter(int nCount) '"=C^f  
{ =TyN"0@  
nSplitter = nCount; ^W'\8L  
} e}7qZ^  
} A D~\/V&+  
Px)VDs=k  
lQ)ZsFs=  
/* -O-_F6p'D  
**Utility.java BYwG\2?~  
*/ ^${-^w@,%V  
package NetFox; 011 _(v  
O4( Z%YBe  
v%B^\S3)  
public class Utility { AvhmN5O =  
U<o,`y[Tn  
tpA7"JD  
public Utility() u5%.T0 P  
{ Jw9|I)H  
1jQz%^~  
XnV|{X%]U  
} < R0c=BZ>  
pH)V:BmJ  
//线程睡眠 8`'_ckIgr  
public static void sleep(int nSecond) RYmk6w!w  
{ 1G$kO90  
try{ B*,9{g0m/  
Thread.sleep(nSecond); /ptIxe  
} i7*4hYY  
catch(Exception e) FWPkvL  
{ 5GC{)#4  
e.printStackTrace (); nwW `Q>+#U  
} 0 R^Xn  
} HOXqIZN85  
5Sk87o1E(d  
//日志 `P"-9Ue=  
public static void log(String sMsg) R '"J{oR  
{ |jc87(x <  
System.err.println(sMsg); 7 ?/ Fr(\  
} vhdT"7`U  
%vn rLt$  
fE7[Sk  
public static void log(int sMsg) GT2;o  
{ /zPN9 db  
System.err.println(sMsg); f`H}Y!W(  
} !P#lTyz  
} ${mHbqN  
$wC]S4C  
wGAN"K:e  
/* .(nq"&u-*  
**TestMethod.java ~99Ta]U  
*/ fs7JA=?:  
package NetFox; >.QD:_@:  
q4lL7@_  
jb fMTb4  
public class TestMethod { :^! wQ""  
rzY7f: '  
Q]7r?nEEhW  
public TestMethod() 4 ILCvM  
{ ///xx/weblogic60b2_win.exe p}O@ %*p .  
try{ sR'rY[^/|  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I6h{S}2  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); - C8 h$P  
SiteFileFetch fileFetch = new SiteFileFetch(bean); (F~eknJ  
fileFetch.start(); T?NwSxGo  
} prhFA3 rW.  
catch(Exception e){e.printStackTrace ();} |L<oKMZY  
a!xKS8-S==  
# 1I<qK  
} &+ JV\  
bWG}>{fj  
*>zr'Tt,W  
public static void main(String[] args) O. @_2  
{ Vg&` f  
new TestMethod(); +X"TiA7{j  
} 6e/2X<O  
} ~@MIG  
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