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http断点续传简单实现(java)

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/* \m.ap+dFa  
**SiteFileFetch.java /`M> 3q[  
*/ uS9:cdH  
package NetFox; +3HukoR(  
import java.io.*; 5yvaY "B  
import java.net.*; BrW1:2w >\  
\5+?wpH  
|4UU`J9M  
public class SiteFileFetch extends Thread { 4=j,:q  
q|E0Y   
}E01B_T9z  
SiteInfoBean siteInfoBean = null; //文件信息Bean J{GtH[  
long[] nStartPos; //开始位置 {K{&__Nk  
long[] nEndPos; //结束位置 Hpo/CY/  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 zeqP:goy  
long nFileLength; //文件长度 }uI(D&?+h  
boolean bFirst = true; //是否第一次取文件 -ff|Xxar{  
boolean bStop = false; //停止标志  &cjE+  
File tmpFile; //文件下载的临时信息 KY)r kfo B  
DataOutputStream output; //输出到文件的输出流 DzZ)a E  
0D;MW  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类)  b>N) H  
public SiteFileFetch(SiteInfoBean bean) throws IOException jzuOs,:R  
{ 1B;-ea  
siteInfoBean = bean; ryz [A:^G  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); "W_C%elg  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); oo{5 :  
if(tmpFile.exists ()) !i0jk,[B=  
{ ;WQ@dC  
bFirst = false; us&!%`  
read_nPos(); 8\Y/?$on  
} >".,=u'  
else Sz\"*W;>  
{ T[w]w  
nStartPos = new long[bean.getNSplitter()]; < bHu9D  
nEndPos = new long[bean.getNSplitter()]; RB5fn+FiZ  
}  N-x~\B!  
`={s*^Ta  
_":yUa0D  
5XO eYO{  
} [OI&_WIw  
,`7;S,f  
UcCkn7}  
public void run() Nw'3gJ:  
{ Kt WG2  
//获得文件长度  } z4=3 '  
//分割文件 {(}Mu R  
//实例FileSplitterFetch o C]tEXJ  
//启动FileSplitterFetch线程 =*q|568  
//等待子线程返回 o E+s8Q  
try{ c5uT'P"  
if(bFirst) `{g8A P3  
{ N0be=IO5#  
nFileLength = getFileSize(); aqvt$u8  
if(nFileLength == -1) _VU/j9<+  
{ mU1lEx$  
System.err.println("File Length is not known!"); ^(ks^<}  
} CPq{M.B  
else if(nFileLength == -2) G Q&9b_  
{ eSZS`(#!(  
System.err.println("File is not access!"); Jji~MiMn  
} $or?7 w>  
else ^7`"wj14  
{ (7RxCo=X  
for(int i=0;i<nStartPos.length;i++) sIuk  
{ QMI&?Q:=  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ~Mv@Bl  
} 'hl>pso.  
for(int i=0;i<nEndPos.length-1;i++) L&1VPli  
{ z\Y+5<a  
nEndPos = nStartPos[i+1]; e{edI{g  
} ]KGLJ~hm>  
nEndPos[nEndPos.length-1] = nFileLength; nG;wQvc  
} JZp*"UzQr  
} ?45kN=%*s  
\1 4"Bgj1  
$AAv%v  
//启动子线程 DSY:aD!  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O YGh!sW  
for(int i=0;i<nStartPos.length;i++) 37 )Dx  
{ LTu cs }  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P&3'N~k-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VOBzB]  
nStartPos,nEndPos,i); "J]_B  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eR r.j  
fileSplitterFetch.start(); .5I!h !  
} }7CMXw [  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ` bd  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~YHy '.  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y:C7S~  
nEndPos = " + nFileLength); >W"gr]R<  
// fileSplitterFetch[nPos.length-1].start(); H4LZNko  
O=}4?Xv  
O"4Q=~Y  
//等待子线程结束 )/H=m7}1h  
//int count = 0; _[-+%RP  
//是否结束while循环 ]gYnw;W$  
boolean breakWhile = false; >N>WOLbb7(  
U'S}7gya  
M:|Z3p K  
while(!bStop) "bAkS}(hB(  
{ )xiiTkJd5  
write_nPos(); _^Lv8a3(O  
Utility.sleep(500); <A&mc,kj  
breakWhile = true; >*H>'O4  
8DbXv~3@  
y0qrl4S)v  
for(int i=0;i<nStartPos.length;i++) -x2/y:q`  
{ zVe@`gc  
if(!fileSplitterFetch.bDownOver) b:/;  
{ !YL|R[nDH|  
breakWhile = false; 7''l\3mIn  
break; 2?ac\c6"  
} ~H/|J^ J  
} 78>)<$+d  
if(breakWhile) c%v[p8 %  
break; jq#_*&Eg]  
Y 3r m')c  
zu&5[XL  
//count++; X-9>;Mb~y  
//if(count>4) H];|<G  
// siteStop(); f>ohu^bd  
} mh]'/C_*<w  
Rkm1fYf  
V0 x[sEW  
System.err.println("文件下载结束!"); $.kP7!`:,  
} %se4aeOrX  
catch(Exception e){e.printStackTrace ();} ![3#([>4>  
} 9tsI1]1[m  
)ALPMmlRs  
`,d*>  
//获得文件长度 SV16]Vc  
public long getFileSize() B PTQm4TN  
{ &Yi)|TU3'R  
int nFileLength = -1; q}>1Rr|U`  
try{ M3@Wb@  
URL url = new URL(siteInfoBean.getSSiteURL()); jW*|Mu>2  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9Y!N\-x`  
httpConnection.setRequestProperty("User-Agent","NetFox"); yjUZ 40Dq  
\#.,@g  
5G=<2;  
int responseCode=httpConnection.getResponseCode(); py.lGywb_  
if(responseCode>=400) [2#5;')  
{ K,e"@G  
processErrorCode(responseCode); ){`s&?M0  
return -2; //-2 represent access is error ;EbGW&T  
} Gm;)Om_  
Vy0s%k  
sm5\> L3V  
String sHeader; t!RR5!  
{'VP_ZS1v  
zY~  
for(int i=1;;i++) _O)xE9t#ru  
{ z(2pl}  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B*7Y5_N  
//Utility.log(in.readLine()); RY'f%c  
sHeader=httpConnection.getHeaderFieldKey(i); b/'{6zn  
if(sHeader!=null) =!T@'P?  
{ `s5<PCq  
if(sHeader.equals("Content-Length"))  H"czF  
{ u~n*P``{  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,T@+QXh  
break; pSp/Qpb-B  
} f =@'F=  
} 1=(jpy  
else g^|}e?  
break; sC >_ulkoa  
} |U{9Yy6p  
} c'cK+32  
catch(IOException e){e.printStackTrace ();} ^hq+ L^$^  
catch(Exception e){e.printStackTrace ();} 0/K?'&$yvb  
(5- w>(  
HS>(y2}'  
Utility.log(nFileLength); :T^!<W4  
2N*XzVplN  
e??tp]PLn  
return nFileLength; )!6JSMS  
} Uytq,3Gj6  
kFKc9}7W  
9U[Gh97Sf  
//保存下载信息(文件指针位置) \kSoDY`l&  
private void write_nPos() iV9wqUkMv  
{ .T~<[0Ex+U  
try{ ZK:dhwer  
output = new DataOutputStream(new FileOutputStream(tmpFile)); X&C&DTB  
output.writeInt(nStartPos.length); 1Q_  C  
for(int i=0;i<nStartPos.length;i++) TdGda'C  
{ A/5??3H  
// output.writeLong(nPos); 8Aq [@i  
output.writeLong(fileSplitterFetch.nStartPos); S1jI8 #z}_  
output.writeLong(fileSplitterFetch.nEndPos);  1B}q?8n  
} ?%RAX CK  
output.close(); PJd7t% m;  
} $ti*I;)h4  
catch(IOException e){e.printStackTrace ();} n(X{|?  
catch(Exception e){e.printStackTrace ();} 6 3TeTGp$  
} Xae0xs  
GMk\ l  
5\\#kjjx  
//读取保存的下载信息(文件指针位置) ggluQGA  
private void read_nPos() B$A`thQp  
{ mL5Nu+#  
try{ C]@v60I  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7  s+j)  
int nCount = input.readInt(); Za,MzKd=  
nStartPos = new long[nCount]; hz:^3F`>/&  
nEndPos = new long[nCount]; Q1ox<-  
for(int i=0;i<nStartPos.length;i++) g)Ep'd-w"  
{ @ P:b\WCI  
nStartPos = input.readLong(); 4Vv~  
nEndPos = input.readLong(); L >* F8|g  
} rw CFt6;v  
input.close(); 3k%fY  
}  Iw07P2  
catch(IOException e){e.printStackTrace ();} ? PIq/[tk  
catch(Exception e){e.printStackTrace ();} O &/9wi>!q  
} gK&MdF*  
U,G!u=+  
J A=9EnTU  
private void processErrorCode(int nErrorCode) N+)gYb6h  
{ #9R[%R7Nz  
System.err.println("Error Code : " + nErrorCode); iCz0T,  
} 1/ZvcdYB  
R1!F mZW8  
.,-,@ZK  
//停止文件下载 S%NS7$`a  
public void siteStop() E$u9Jbe  
{ +2DzX/3  
bStop = true; 7m4gGkX#r  
for(int i=0;i<nStartPos.length;i++) dwH8Zg$B  
fileSplitterFetch.splitterStop(); $0-}|u]5U  
?MW *`U  
TO(2n8'fdO  
} nZ4JI+Q)~  
} Dw%V.J/&o  
//负责部分文件的抓取 |JUb 1|gi  
**FileSplitterFetch.java y v$@i A  
*/ /.knZ_aJ!  
package NetFox; ZWtlOP#]  
YmBo/IM  
3SI~?&HU!/  
import java.io.*; A#b`{C~l  
import java.net.*; \n&l  
pBZf=!+E  
"e3T;M+  
public class FileSplitterFetch extends Thread { ZqDanDM  
%OV)O-  
B-R& v8F  
String sURL; //File URL IIZu&iZo\  
long nStartPos; //File Snippet Start Position cC4 2b2+  
long nEndPos; //File Snippet End Position {?!0<0  
int nThreadID; //Thread's ID a>05Yxw  
boolean bDownOver = false; //Downing is over M1Frn n  
boolean bStop = false; //Stop identical 3 L:s5  
FileAccessI fileAccessI = null; //File Access interface %',bCd{QW  
o4[  
(Yv)%2  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V(?PKb-w)  
{ KTmduf7DL  
this.sURL = sURL; 2!w5eWl,  
this.nStartPos = nStart; 1#Ls4+]5  
this.nEndPos = nEnd; 0\y{/P?I$  
nThreadID = id; Vgj&h dbd  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dj;Zzt3  
} \ZOH3`vq  
=V[ey  
G\;a_]Q  
public void run() 9B&fEmgEc?  
{ sOf;I]E|  
while(nStartPos < nEndPos && !bStop) pBbfU2p  
{ ZaZm$.s n  
i3SrsVSG  
liuw!  
try{ NI%&Xhn!*>  
URL url = new URL(sURL); ; 1^ ([>|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zK_+UT  
httpConnection.setRequestProperty("User-Agent","NetFox"); rgK:ujzW!  
String sProperty = "bytes="+nStartPos+"-"; oPbxe  
httpConnection.setRequestProperty("RANGE",sProperty); -".q=$f  
Utility.log(sProperty); f6*6*=  
c@&`!e  
 W>HGB  
InputStream input = httpConnection.getInputStream(); lG>,&(  
//logResponseHead(httpConnection); eF06B'uL  
}j_2K1NS{  
Rt6(y #dF  
byte[] b = new byte[1024]; *URBx"5XZ  
int nRead; +%'!+r l  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %Ums'<xJ  
{ e{}oQK  
nStartPos += fileAccessI.write(b,0,nRead); ALO0yc  
//if(nThreadID == 1) }iE!( l  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <pXF$a:s  
} Ht,dMt>:  
"N*bV  
<8,,pOb  
Utility.log("Thread " + nThreadID + " is over!"); ~w,c6 Z  
bDownOver = true; |}07tUq  
//nPos = fileAccessI.write (b,0,nRead); pFW^   
} EG&97l b  
catch(Exception e){e.printStackTrace ();} PCkQ hR  
} Xk]:]pl4W  
} t~0!K;nn  
+k<0: Fi  
7/>#yR  
//打印回应的头信息 G< _<j}=  
public void logResponseHead(HttpURLConnection con) Ui43&B  
{ W-8U~*/  
for(int i=1;;i++) } Tz<fd/  
{ Gdu5 &]H#6  
String header=con.getHeaderFieldKey(i); ,ej89  
if(header!=null) ~ _G W  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %={[e`,  
Utility.log(header+" : "+con.getHeaderField(header)); .VG5 / 6zp  
else M}Obvl  
break; H~ `JAplr  
} xJ(}?0h-X  
} XN Gw@$  
,VYUQE>\  
0Uf.aP  
public void splitterStop() D9 \!97  
{ B ?%g@d-;  
bStop = true; "+sl(A3`U  
} 6Qw5_V^0o  
P~^VLnw  
bSvr8FY3d  
} D~T;z pS  
q?0&&"T}  
- xE%`X  
/* 5oTj^W8M(  
**FileAccess.java $O[$<D%H  
*//文件访问(定位,写) ]; Z[V  
package NetFox; G}V5PEF]`  
import java.io.*; dVKctt'C  
/JGET  
SsBiCctn  
public class FileAccessI implements Serializable{ $TZjSZ1w  
dc=}c/6x  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /!A?>#O&.  
RandomAccessFile oSavedFile; Bbj%RF2,  
long nPos; O =gv2e  
MY w3+B+Jj  
<nk7vo?Ks  
public FileAccessI() throws IOException /3KPK4!m  
{ (`)ZR %i  
this("",0); {^*K@c  
} x"83[0ib  
T)lkT?  
w,!IvDCAw  
public FileAccessI(String sName,long nPos) throws IOException oU)Hco"_k  
{ h6;vOd~%  
oSavedFile = new RandomAccessFile(sName,"rw"); d9Uv/VGp  
this.nPos = nPos; k%Wj+\93 f  
oSavedFile.seek(nPos); e$l*s/"0t  
} ^hRx{A  
!L3\B_#  
J>dIEW%u  
public synchronized int write(byte[] b,int nStart,int nLen) uFYcVvbT@  
{ zXZXp~7)  
int n = -1; wmDO^}>ZP  
try{ 12o6KVV^x  
oSavedFile.write(b,nStart,nLen); iPCDxDLN3V  
n = nLen; 1haNpLfS>  
} 3k# h!Z  
catch(IOException e) yB5JvD ?  
{ t b>At*tO  
e.printStackTrace (); r0/aw  
} wB+X@AA  
xRbtiFk9H  
rr^?9M*{V  
return n; pB:/oHV  
} z2U^z*n{  
3,yzRb  
g@|2z  
} Px?zih!6  
FjV)QP H  
oxNQNJ!X  
/* ;:1o|>mX  
**SiteInfoBean.java C+%6N@  
*/ *X\J[$!  
package NetFox; NnRX0]  
k*K.ZS688  
a)QSq<2*  
public class SiteInfoBean { +!cibTQTT  
ZtGtJV"H  
S0w:R:q}L  
private String sSiteURL; //Site's URL g+]o=@  
private String sFilePath; //Saved File's Path \rM5@ Vf  
private String sFileName; //Saved File's Name R q`j|tY  
private int nSplitter; //Count of Splited Downloading File 61Wh %8-  
Sf'uKSX1%  
jidRh}>a=  
public SiteInfoBean() yrG=2{I  
{//nSplitter的缺省值为5 ZVz`g]  
//default value of nSplitter is 5 _sK{qQxvM=  
this("","","",5); |_m N:(3  
} 2= zw !  
@tlWyUju  
)x3p7t)#  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |f3 :9(p  
{ 6,~]2H'zq  
sSiteURL= sURL; H>F j  
sFilePath = sPath; p:zRgwcn  
sFileName = sName; heScIe N^`  
this.nSplitter = nSpiltter; X16vvsjw5  
u]Z;Q_=  
\Vx_$E  
} H;MyT Vl  
r"!xI  
%5!K?,z%  
public String getSSiteURL() @?*; -]#)  
{ ,</Kn~b  
return sSiteURL; g(dReC  
} ) uTFId  
*iVE O  
)]C(NTfxg  
public void setSSiteURL(String value) NqM=Nu\  
{ 9qvl9,*g  
sSiteURL = value; uM,R+)3  
} 1s.>_  
dOVu D(  
V[0 ZNT&  
public String getSFilePath() 6w~Cyu4Ov  
{ [l}H%S   
return sFilePath; $f=6>Kn|^]  
} dF><XZph  
>qZl s'  
a U*}.{<!  
public void setSFilePath(String value) w+$~ ds  
{ &WZ&Tt/)/  
sFilePath = value; .'NTy R  
} )E m`kle  
MzH'<`;BP  
-vv_6Z L[  
public String getSFileName() 0i>p1/kv  
{ intl?&wC  
return sFileName; }Fsr"RER@{  
} 5\}E4y  
@VQ<X4 Za  
L{oG'aK4  
public void setSFileName(String value) _9'hmej  
{ [5]n,toAh  
sFileName = value; "R"{xOQl  
} biV NZdA  
7CH.BY  
I&`aGnr^^  
public int getNSplitter() _bt9{@)  
{ frc9   
return nSplitter; /vC!__K9:  
} 7A h   
]Ljb&*IEj  
x_CY`Y  
public void setNSplitter(int nCount) YFDOp *  
{ R{ udV  
nSplitter = nCount; 1Vc~Sa  
} o]]sm}3N  
} hM[3l1o{|  
w[$oH^7  
w|Ry) [  
/* UyFC\vQ  
**Utility.java Ow(aRWUZD_  
*/ 7!wc'~;  
package NetFox; 3D^cPkX  
Uf MQ?(,  
\XwC|[%P  
public class Utility { +o):grWvQ  
s6r(\L_Im  
q|0l>DPRp  
public Utility() hA;Ai:8  
{ [!MS1v c;  
sPVE_n  
|3 Iug  
} 'oH3|  
e-OKv#]  
//线程睡眠 IZ\fvYp  
public static void sleep(int nSecond) A3*(c3  
{ gf?N(,  
try{ f:y1eLl3  
Thread.sleep(nSecond); zR <fz  
} z 2jC48~  
catch(Exception e) k"C'8<T)'  
{ y?P`vHf  
e.printStackTrace (); ^b}Wl0Fn  
} z&Aya*0v`  
} MT:VQ>f C  
sOiM/} O]  
//日志  rV4K@)~  
public static void log(String sMsg) <=D  a  
{ G "!v)o  
System.err.println(sMsg); -(>Ch>O  
} KV$4}{  
 I8`$a  
ipl,{  
public static void log(int sMsg) $45.*>,  
{ ;ISe@ yR;  
System.err.println(sMsg); ZO%iyc%  
} A0U9,M  
} U*E)y7MY  
,G5[?H;ZN  
yP>025o't  
/* 7S&$M-k  
**TestMethod.java 3-,W? "aC  
*/ 2%6 >)|  
package NetFox; gzqp=I[%  
y Vm>Pj6  
-{8K/!  
public class TestMethod { %+Y wzL{  
 y1T(R#  
CaO-aL  
public TestMethod() q<! -Anc  
{ ///xx/weblogic60b2_win.exe tq3Rc}  
try{ *8m['$oyV  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EwU)(UK  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +xU({/  
SiteFileFetch fileFetch = new SiteFileFetch(bean); c-}[v<o  
fileFetch.start(); pMy:h   
} =-X-${/  
catch(Exception e){e.printStackTrace ();} s.Bb@Jq  
3l41"5Fy&  
3 V>$H\H  
} rF"p7  
h~](9e s  
KR%WBvv   
public static void main(String[] args) V+y"L>K  
{ x: _[R{B  
new TestMethod(); &KAe+~aPm  
} qy)~OBY  
} mfaU_Vo&  
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