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http断点续传简单实现(java)

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/* 9n#Em  
**SiteFileFetch.java Iib39?D W  
*/ xK3}z N$T  
package NetFox; 2{E"#}/  
import java.io.*; z(&~O;;N#  
import java.net.*; I,xV&j+<  
2E":6:Wsw  
m@){@i2.  
public class SiteFileFetch extends Thread { <ny)yK  
eDPmUlC+-  
Gv3AJ'NL  
SiteInfoBean siteInfoBean = null; //文件信息Bean `<:D.9vO "  
long[] nStartPos; //开始位置 5<y pK`Kq  
long[] nEndPos; //结束位置 I6E!$ }  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 !DUC#)F  
long nFileLength; //文件长度 Hs~u&c  
boolean bFirst = true; //是否第一次取文件 NXw$PM|+R  
boolean bStop = false; //停止标志 g$jZpU  
File tmpFile; //文件下载的临时信息 9(;I+.;8k  
DataOutputStream output; //输出到文件的输出流 D~s TQfWr  
CAl]Kpc  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) n@Ar%%\  
public SiteFileFetch(SiteInfoBean bean) throws IOException 3r (i=ac0  
{ +Ks! 9d*k<  
siteInfoBean = bean; ,[{)4J$MV  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); u`2[V4=L  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 06#40-   
if(tmpFile.exists ())  )6 _+  
{ 4/tp-dBip  
bFirst = false; }QqmDK.  
read_nPos(); `fRp9o/  
} oG_-a(N  
else xiW;Y{kZ  
{ Q{0!N8']"  
nStartPos = new long[bean.getNSplitter()]; E{Ux|r~  
nEndPos = new long[bean.getNSplitter()]; JBKCa 3  
} ZRd,V~iz  
ZOK,P  
Dqw?3 KB  
Z/S7ei@56  
} eQRY xx{  
vF,iHzv  
+=/FKzT<  
public void run() jo_wBJKE  
{ GrB+Y!{{  
//获得文件长度 U- a+LS  
//分割文件 hi30|^l-  
//实例FileSplitterFetch  :nHa-N3  
//启动FileSplitterFetch线程 }H4Z726  
//等待子线程返回 Rn-RMD{dh  
try{ LT3ViCZ-n  
if(bFirst) dlx "L%  
{ UpU2H4  
nFileLength = getFileSize(); R}-<ZJe  
if(nFileLength == -1) +W6QtB6  
{ kCu"G  
System.err.println("File Length is not known!"); ~X`_ g/5X  
} };:+0k/  
else if(nFileLength == -2) MZ{gU>K+  
{ _8U 5mW  
System.err.println("File is not access!"); pUz;e#J|  
} RnX:T)+o  
else f/Lyc=- ]  
{ mXH\z  
for(int i=0;i<nStartPos.length;i++) q)ns ui(  
{ nKzS2 u=:Y  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); @,Iyn<v{B  
} `bJ+r)+5  
for(int i=0;i<nEndPos.length-1;i++) & bwhD.:=  
{ ; SS/bS|  
nEndPos = nStartPos[i+1]; 8"zFTP*;u  
} d,_Ky#K5b  
nEndPos[nEndPos.length-1] = nFileLength; n!r<\4I  
} _U"9#<  
} Whd2mKwiO  
;ss,x  
uq>\pO&P  
//启动子线程 /8(\AuDT  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QyGTm"9l  
for(int i=0;i<nStartPos.length;i++) GYX/G>-r  
{ s 9Y'MQo*  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0 2lI-xHe  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Vk/!_)  
nStartPos,nEndPos,i); 1FCHqqZ=  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /7nircXj@  
fileSplitterFetch.start(); \=O['#  
} Y'YvVI  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DRn]>IFU  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1);  IwfJDJJ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8<Y*@1*j  
nEndPos = " + nFileLength); W?n)IBj8  
// fileSplitterFetch[nPos.length-1].start(); ya<nD'%9  
z)RJUmY3B  
JFyw,p&xB  
//等待子线程结束 {*Ag[HS0u  
//int count = 0; Gd:TM]rJ  
//是否结束while循环 H+oQ L(i|_  
boolean breakWhile = false; t4RI%m\  
&.zG?e.  
't+ J7  
while(!bStop) g/o@,_  
{ `FjU2 O  
write_nPos(); J 8z|ua  
Utility.sleep(500); "h-G=vo,kl  
breakWhile = true; <}@*i  
g9A8b(>F&@  
6`tc]a"#Zb  
for(int i=0;i<nStartPos.length;i++) Rd?8LLz  
{ , : I:F  
if(!fileSplitterFetch.bDownOver) zPonG d1  
{ LRJY63A  
breakWhile = false; "G^Z>Z-`  
break; E^)>9f7  
} m zh8<w?ns  
} {<~oa+"  
if(breakWhile) $S_xrrE#  
break; M x/G^yO9  
:7,j%ELic  
rjFIK`_w  
//count++; XYi-o][Mf  
//if(count>4) ,G q?  
// siteStop(); e5g# a}  
} "Cj {Z@n  
[9wuaw"~[Z  
Q"6:W2#v  
System.err.println("文件下载结束!");  }de {-  
} Yq6e=?-  
catch(Exception e){e.printStackTrace ();} <sALA~p|0  
} 7Rba@ cs9  
Xjy5Yj  
|6cz r  
//获得文件长度 PQu_]cXI  
public long getFileSize() Ix-bJE6+I,  
{ > FVBn;1  
int nFileLength = -1; {Dc{e5K  
try{ N(6Q`zs  
URL url = new URL(siteInfoBean.getSSiteURL()); >1}RiOd3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4"om;+\  
httpConnection.setRequestProperty("User-Agent","NetFox"); I%^Bl:M  
K1th>!JW'  
6n|R<DO%\  
int responseCode=httpConnection.getResponseCode(); :7WeR0*%  
if(responseCode>=400) BHNcE*U}@?  
{ CAbeb+O  
processErrorCode(responseCode); 9J*M~gKbz  
return -2; //-2 represent access is error .T2P%Jn.  
} pR3@loFQ`o  
>@Nn_d  
m-< "`:+  
String sHeader; X,] E {  
LU-,B?1  
c:J;Q){Xz  
for(int i=1;;i++) '`)r<lYN,  
{ T J!d 7  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A~@u#]]<n  
//Utility.log(in.readLine()); (~6D`g`B  
sHeader=httpConnection.getHeaderFieldKey(i); W~!uSrY  
if(sHeader!=null) lYF~CNvE  
{ W Ai91K@  
if(sHeader.equals("Content-Length")) d)R7#HLZ7  
{ CeZ+!-lG  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S'h{["P~ 0  
break; q':P9 o*N?  
} =tKb7:KU  
} &y} ]^wB  
else ^$!H|  
break; P^)J^{r  
} Z\\'0yuY(  
} ^Fn~@'  
catch(IOException e){e.printStackTrace ();} {o."T/?d'  
catch(Exception e){e.printStackTrace ();} _^k9!V jo  
mRECd Gst  
N!{waPbPi  
Utility.log(nFileLength); ,\DSi&T  
!,(6uO%  
8mmHefZ}2!  
return nFileLength; yUyx&Y/  
} WZ A8D0[  
[X\<C '<  
\#hp,XV>  
//保存下载信息(文件指针位置) )B!64'|M  
private void write_nPos() F?!X<N{  
{ 1.U9EuI  
try{ 1v?|n8  
output = new DataOutputStream(new FileOutputStream(tmpFile)); @ptE&m  
output.writeInt(nStartPos.length); S^ ,q{x*T  
for(int i=0;i<nStartPos.length;i++) &gr)U3w  
{ 3d>3f3D8;  
// output.writeLong(nPos); e8Y;~OAj[  
output.writeLong(fileSplitterFetch.nStartPos); <hv {,1p-r  
output.writeLong(fileSplitterFetch.nEndPos); aANzL  
} !&f>,?wlP  
output.close(); (2l?~CaK  
} NbyXi3@v  
catch(IOException e){e.printStackTrace ();} ;bMmJ>[l-  
catch(Exception e){e.printStackTrace ();} `{B<|W$=  
} W]-c`32~S  
vJ a?5Jr  
*#| lhf'  
//读取保存的下载信息(文件指针位置) VGVb3@  
private void read_nPos() ?r%kif)  
{ :~ ; 48m  
try{ B.oD9 <9  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y.6Yl**l  
int nCount = input.readInt(); rHMr8,J;  
nStartPos = new long[nCount];  &$ x1^  
nEndPos = new long[nCount]; !D!1%@ e  
for(int i=0;i<nStartPos.length;i++) iiWm>yy  
{ yQ/E0>Uj!  
nStartPos = input.readLong(); Q2 S!}A  
nEndPos = input.readLong(); ? kBX:(g  
} B=;p wX  
input.close(); 5i eF8F%  
} ]iHSUP  
catch(IOException e){e.printStackTrace ();} =9;2(<A  
catch(Exception e){e.printStackTrace ();} }R\;htmc;  
} \Q~HL_fy|Y  
"c2{n,  
]tnf< 5x  
private void processErrorCode(int nErrorCode) )bkJ[ '9  
{ DZ*m"Bi  
System.err.println("Error Code : " + nErrorCode); .271at#-  
} p4sU:  
;&~9k?v7L  
,mY3oyu  
//停止文件下载 LV6BSQyQ  
public void siteStop() \5q0nB@i5y  
{ h)o5j-M>4  
bStop = true; G,,7.%eib=  
for(int i=0;i<nStartPos.length;i++) -h`[w:  
fileSplitterFetch.splitterStop(); iYR`|PJi  
#sJL"GB  
~1g)4g~  
} G1?m}{D)  
} Ce.*yO<-  
//负责部分文件的抓取 pLtAusx  
**FileSplitterFetch.java hVLV Mqd  
*/ E8Y(C_:s  
package NetFox; bH1MDBb2  
v9K=\ j  
FC&841F  
import java.io.*; }u&,;]  
import java.net.*; /8Xd2-  
<3WaFi u  
rT/4w#_3  
public class FileSplitterFetch extends Thread { U3rpmml  
RGC DC*\  
3zsjL=ta  
String sURL; //File URL 032PR;]  
long nStartPos; //File Snippet Start Position K[s!3.u  
long nEndPos; //File Snippet End Position _uQxrB"9  
int nThreadID; //Thread's ID .cCB,re  
boolean bDownOver = false; //Downing is over tFrNnbmlQ  
boolean bStop = false; //Stop identical \O G`+"|L  
FileAccessI fileAccessI = null; //File Access interface _WB*ArR  
CWx_9b zk  
dxk~  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1_MaaA;ow"  
{ DMpNm F>  
this.sURL = sURL; FXO{i:Zo  
this.nStartPos = nStart; ^Sj*  
this.nEndPos = nEnd; : kw14?]_  
nThreadID = id; #Ab,h#f*7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C[2LP$6*/  
} 1yT\|2ARZ%  
G W~ZmK  
XMi)PXs$  
public void run() lDF26<<\`  
{ 88~ lP7J  
while(nStartPos < nEndPos && !bStop) 3^2P7$W=   
{ wU(N<9  
_]q%Hve  
=CGB}qU l0  
try{ r6 :c<p[c  
URL url = new URL(sURL); n\'@]qG)Z4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c3X8Wi7m  
httpConnection.setRequestProperty("User-Agent","NetFox"); csCi0'u  
String sProperty = "bytes="+nStartPos+"-"; .~jn N  
httpConnection.setRequestProperty("RANGE",sProperty); RAY.]:}jr  
Utility.log(sProperty); =qy{8MsjA  
a0*qK)gH  
)sBbmct_S  
InputStream input = httpConnection.getInputStream(); :j[a X7Sq2  
//logResponseHead(httpConnection); Y V#|qb  
=Xu(Js-  
jQRl-[n  
byte[] b = new byte[1024]; NoD\t(@h  
int nRead; !^_G~`r$2J  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q%\rj?U_  
{ jdW#; ]7+y  
nStartPos += fileAccessI.write(b,0,nRead); yr, Oq~e  
//if(nThreadID == 1) w W1>#F  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .In8!hjYy4  
} <h[l)-86  
e}bY 9  
r>.^4Z@  
Utility.log("Thread " + nThreadID + " is over!"); kp>AZVk  
bDownOver = true; 8iKupaaOX  
//nPos = fileAccessI.write (b,0,nRead); 4M3{P  
} <F#/wU^9  
catch(Exception e){e.printStackTrace ();} f3M~2jbv'p  
} kf>L  
} 6S6E 1~  
g4=6\vg  
&Rxy]kBA  
//打印回应的头信息 lgei<\6~n5  
public void logResponseHead(HttpURLConnection con) g4CdzN~  
{ xjO((JC  
for(int i=1;;i++) s\dhQZw3  
{ $bo 5:c  
String header=con.getHeaderFieldKey(i); /Q*cyLv  
if(header!=null) m~U2 L  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eHQ3K#M#  
Utility.log(header+" : "+con.getHeaderField(header)); u[yUUYe  
else ?KF.v1w7  
break; ]id5jVY  
} GFmVR2z_+  
} w 7Y>B`wm?  
\[F4ooe  
Ey**j  
public void splitterStop() qw mZOR#  
{ o])2_e5  
bStop = true; xulwn{R s  
} xfqW~&  
itmQH\9 8  
F G5e{  
} WeqQw?-  
MF%>avRj  
wD'LX  
/* SYZS@o  
**FileAccess.java b*@y/ e\u`  
*//文件访问(定位,写) ?iQA>P9B  
package NetFox; f7Fr%*cO  
import java.io.*; .f~x*@  
i~04P  
~e@pL*s  
public class FileAccessI implements Serializable{ +w'{I`QIL0  
jhmWwT/O8^  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *[?DnF+  
RandomAccessFile oSavedFile; n^m6m%J)  
long nPos; Vg^@6zU  
+""8aA  
JkMf+ !  
public FileAccessI() throws IOException Mk"V%)1k  
{ 2~BId&]  
this("",0); A! j4;=}  
} <u9U%V si  
%}%vey  
d,0Yi u.p  
public FileAccessI(String sName,long nPos) throws IOException Mb#-I GZ  
{ ,0=@cJ  
oSavedFile = new RandomAccessFile(sName,"rw"); kb>/R/,9  
this.nPos = nPos; V$7SVq  
oSavedFile.seek(nPos); TtaVvaz~>  
} )^o7%KX  
QX$i ]y%S  
]/y&5X  
public synchronized int write(byte[] b,int nStart,int nLen) 3#@ETt0X(  
{ "jyh.@<  
int n = -1; 38hAg uZX  
try{ Im\{b=vT  
oSavedFile.write(b,nStart,nLen); MxXu&.| _  
n = nLen; @'yD(ZMAz  
} Y=#g_(4*  
catch(IOException e) 4LBMhLy  
{ i1#\S0jN  
e.printStackTrace (); L*VO2YI  
} :"aCl~cy9g  
YLfZ;W|6u  
f9Hm2wV  
return n; {t;{={$  
} XNU[\I  
O)tZ`X;  
>/DyR+?>4  
} 2@ <x%T  
8R6!SB  
JRC+>'}Xj  
/* }"'^.FG^_  
**SiteInfoBean.java u K`T1*_  
*/ p6yC1\U!o  
package NetFox; |W/_S^C  
Rj|8l K;,  
;J[1S  
public class SiteInfoBean { wM;9plYlw0  
,ij"&XA  
45hjN6   
private String sSiteURL; //Site's URL Bk~lE]Q3c7  
private String sFilePath; //Saved File's Path ,\|W,N}~  
private String sFileName; //Saved File's Name T{iv4`'  
private int nSplitter; //Count of Splited Downloading File <[H1S@{W  
f3+@u2Pv  
f@R j;R~Jp  
public SiteInfoBean() C#< :x!  
{//nSplitter的缺省值为5 XZv(B^  
//default value of nSplitter is 5 \I@=EF- &  
this("","","",5); 5Z7<X2  
} N%A[}Y0;MW  
v [_C^;  
:/BU-SFK^  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .]qj];m  
{ $f-f0t'  
sSiteURL= sURL; B?nQUIb:  
sFilePath = sPath; L>Y>b4oy3  
sFileName = sName; O/9dPod  
this.nSplitter = nSpiltter; t&SC>8M<  
l)glT]G3+  
;R E|9GR  
} T<|B1jA  
>5&'_  
(>x4X@b  
public String getSSiteURL() 8Vkw vc  
{ h7NS9CgO  
return sSiteURL; jB*%nB*x  
} ZkW,  
a{7>7%[  
sS, Swgr  
public void setSSiteURL(String value) F#X&Tb{  
{ -bo5/`x  
sSiteURL = value;  eU"!X9  
}  $&96qsr  
0sv#* &0=  
;^}gC}tq  
public String getSFilePath() FY [WdZDZ  
{ uoYG@L2  
return sFilePath; Cg/L/0Ak  
} /2K4ka<?7  
=h?WT*  
y]B?{m``6  
public void setSFilePath(String value) 7u!i)<pn  
{ ){|Bh3XV  
sFilePath = value; *.0}3  
} 1MH[-=[Q  
.v36xXK(  
_uuxTNN0x*  
public String getSFileName() \ %Er%yv)  
{ {(@M0?  
return sFileName; X !g"D6'  
} 1D03Nbh|5  
|*W`}i  
$R3]y9`?  
public void setSFileName(String value) 0b9;v lGq$  
{ PpD ?TAlA  
sFileName = value; nc#}-}`5  
} 0Zp) DM  
37DyDzW)'  
,y}?Z 8?63  
public int getNSplitter() e`%U}_[d  
{ @vdBA hXk  
return nSplitter; hA.?19<Z  
} Vu '3%~  
-y70-K3  
Z,%^BAJ  
public void setNSplitter(int nCount) 6]yYiz2Xn  
{ &FF%VUfQJ  
nSplitter = nCount; 96UL](l(`  
}  ")MjR1p  
} .5*h']iFr1  
=  *7K_M&  
{<{ O!  
/* !63p?Q=  
**Utility.java ct+ ;W  
*/ g5X;]%:  
package NetFox; ;uj&j1  
cRPW  
;/w-7O:  
public class Utility { Q H:k5V~  
<rZ( B>$  
K' xN>qc  
public Utility() 9P;}P! W  
{ xT7JGQ[|  
P` Hxj> {  
InnjZ>$  
} @j*K|+X"  
(3Hz=k_  
//线程睡眠 R57>z`;  
public static void sleep(int nSecond) @>n7  
{ kR2kV"-l  
try{ DPCB=2E  
Thread.sleep(nSecond); r(;sX  
} n qSjP5  
catch(Exception e) ME"B1 Se\  
{ n1+1/  
e.printStackTrace (); ?.t naE  
} ru#,pJ=O(  
} p4QQ5O$;  
qdkhfm2(K  
//日志 Bw _^"e8X  
public static void log(String sMsg) 'B dZN  
{ Z<L|WRe  
System.err.println(sMsg); cPD&xVwq>  
} IE7%u 92  
}71a3EUK  
\ng!qN  
public static void log(int sMsg) `}t<5_  
{ qxKW% {6o  
System.err.println(sMsg); {j$:9  H  
} 2P3,\L  
} [B<htD&  
0c6b_%Rd  
KE>|,U r  
/* v_M-:e3`  
**TestMethod.java xQLVFgd  
*/ @r7ekyO8)  
package NetFox; Vwxb6,}Z  
P2la/jN  
bMe/jQuL.$  
public class TestMethod { X{cFq W7  
gR7in!8  
D%[yAr;r  
public TestMethod() mX8k4$z  
{ ///xx/weblogic60b2_win.exe .[mI9dc  
try{ ?8AV-rRX  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v@m2c_,  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sz;B-1^6  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ykAZP[^'  
fileFetch.start(); F|mppY'<J  
} Y:f"Zx  
catch(Exception e){e.printStackTrace ();} u^2)oL  
kA c8[Hn  
>6yA+?[:  
} i7rO 5<  
p;#@#>h  
\ @XvEx%  
public static void main(String[] args) B^|^hZZ>  
{ vndD#/lXq  
new TestMethod(); @fz0-vT,  
} .J=<E  
} LtrE;+%2oz  
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