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http断点续传简单实现(java)

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/* ~A >o O-0K  
**SiteFileFetch.java l$XA5#k  
*/ :p-Y7CSSu  
package NetFox; iJP{|-h  
import java.io.*; Z"tQp Jg  
import java.net.*; <lo`q<q  
GqUSVQ  
)%mAZk-*;^  
public class SiteFileFetch extends Thread { 3{3/: 7  
` clB43 i  
i6>R qP!69  
SiteInfoBean siteInfoBean = null; //文件信息Bean pP\h6b+B  
long[] nStartPos; //开始位置 n,nisS  
long[] nEndPos; //结束位置 }O*WV1  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 V/bH^@,sA  
long nFileLength; //文件长度  aZgNPw  
boolean bFirst = true; //是否第一次取文件 )w"0w(   
boolean bStop = false; //停止标志 0Q1/n2V  
File tmpFile; //文件下载的临时信息 (=JueF@J  
DataOutputStream output; //输出到文件的输出流 ( u f5\}x  
j=j+Nf$  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 9#@Zz4Ww  
public SiteFileFetch(SiteInfoBean bean) throws IOException &r@H(}$1\  
{ !Z s,-=^D  
siteInfoBean = bean; SE!L :  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); e1P7 .n}  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); -,GEv%6c  
if(tmpFile.exists ()) [hU=m S8=^  
{ B||c(ue  
bFirst = false; kp`0erJqw  
read_nPos(); 3*WS"bt  
} F]5\YYXO  
else O5;-Om  
{ o!Fl]3F  
nStartPos = new long[bean.getNSplitter()]; Yu3_=: <C  
nEndPos = new long[bean.getNSplitter()]; i<iXHBs  
} <SQ(~xYi  
QS\ x{<e/  
btQet.  
N!m%~kS9k<  
} T %/  
%F5 =n"  
,so4Lb(vG  
public void run() !}q."%%J_%  
{ =pp:j`B9(  
//获得文件长度 Z#7U "G-A  
//分割文件 F^rl$#pCS  
//实例FileSplitterFetch F5IZ"Itu(  
//启动FileSplitterFetch线程 W)-hU~^OM  
//等待子线程返回 XGIpUz  
try{ wLMvC{5  
if(bFirst) bi,mM,N/  
{ Ab g$W/(|  
nFileLength = getFileSize(); W5/};K\.  
if(nFileLength == -1) 0N VI +Z$  
{ 7@P656{  
System.err.println("File Length is not known!"); RpN <=  
} Qa?aL  
else if(nFileLength == -2) e\.HWV]I  
{ };p~A-E=  
System.err.println("File is not access!"); `a'` $'j  
} k1iLnza%  
else ('d{t:TsY  
{ b42QBTeg  
for(int i=0;i<nStartPos.length;i++) ~4^p}{  
{ @1.9PR$x  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ]fC7%"nB  
} ][t 6VA  
for(int i=0;i<nEndPos.length-1;i++) $8@+j[>  
{ W5I=X] &  
nEndPos = nStartPos[i+1]; \`gEu{  
} mJ$Htyr  
nEndPos[nEndPos.length-1] = nFileLength; CB]l[hM$  
} T*\$<-^  
} :#SNpn=@  
A^g>fv  
hVZo"XUb  
//启动子线程 ^ LbGH<#J  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ohplj`X[21  
for(int i=0;i<nStartPos.length;i++) z8tl0gd%D  
{ 7TdQRB  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0||F`24  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b,Lw7MY}[  
nStartPos,nEndPos,i); kW(Kh0x  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k<O y%+C  
fileSplitterFetch.start(); %M6 c0d[9-  
} C8MWIX}  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _ n_sfT6)B  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |."G?*  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I61%H9 ;  
nEndPos = " + nFileLength); ;^ov~PPl  
// fileSplitterFetch[nPos.length-1].start(); >13/h]3  
Hf_'32e3<  
0etwz3NuW  
//等待子线程结束 -t>Z 9  
//int count = 0; M8_R  
//是否结束while循环 G"C;A`6  
boolean breakWhile = false; .qinR 6=  
9A<0zt  
mt^`1ekoY  
while(!bStop) InN{^uN  
{ cD8Ea(  
write_nPos(); @T/qd>T o  
Utility.sleep(500); P57GqT  
breakWhile = true; m9Il\PoTq  
-p^'XL*Z  
?OO%5PSen  
for(int i=0;i<nStartPos.length;i++) ^Po,(iIn  
{ -%=RFgU4  
if(!fileSplitterFetch.bDownOver) N"~ qoJO  
{ b- uZ"Kf^  
breakWhile = false; 0V7 _n  
break; ~4+8p9f  
} p}BGw:=  
} -xTKdm D  
if(breakWhile) f| =# q  
break; Z+,CL/  
gi 5XP]z  
g@(4ujOT  
//count++; ZR6&AiL(Bj  
//if(count>4) %HVD^. V  
// siteStop(); 22'vm~2E  
} & L'6KEahR  
6Wb!J>93  
_[%n ~6  
System.err.println("文件下载结束!"); nUqL\(UuY  
} ]Y=S  
catch(Exception e){e.printStackTrace ();} ]7l{g9?ZtV  
} ( QKsB3X  
{RJ52Gx(  
}v&K~!*  
//获得文件长度 ( mt*y]p?  
public long getFileSize() `OBl:e  
{ g+3Hwtl  
int nFileLength = -1; |C4o zl=O?  
try{ F#KF6)P  
URL url = new URL(siteInfoBean.getSSiteURL()); [brkx3h  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UT~4Cfb  
httpConnection.setRequestProperty("User-Agent","NetFox"); q55M8B 4w  
\eT/%$  
3wo'jOb  
int responseCode=httpConnection.getResponseCode(); I<KCt2:X  
if(responseCode>=400) ovSH}h!  
{ "G@E6{/  
processErrorCode(responseCode); Y=|CPE%V  
return -2; //-2 represent access is error /wlFD,+8  
} I[%M!_+  
ILNXaJ'0a  
5E0wn'  
String sHeader; )Z&HuEg{ZR  
'?b\F~$8  
<a fO 6?`  
for(int i=1;;i++) &AJUY()8  
{ oo\IS\  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Gj*SPU  
//Utility.log(in.readLine()); yduuFK  
sHeader=httpConnection.getHeaderFieldKey(i); wZ O@J|  
if(sHeader!=null) ^t7_3%%w  
{ oLd:3,p}  
if(sHeader.equals("Content-Length")) X= SG  
{ 8M~u_`6  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CxkMhd8qz  
break; nqrDT1b**  
} T"IW Jpc  
} 1B(G]o_>!  
else zv,\@Z9.($  
break; /RMer Xj  
} PQi }Evxa  
} 5e)i!;7Uv  
catch(IOException e){e.printStackTrace ();} >r~|1kQ.  
catch(Exception e){e.printStackTrace ();} y=wdR|b  
E~}[+X@  
|Cu1uwy  
Utility.log(nFileLength); !*9FKDB{  
yZ?$8r  
y]w )`}Ax  
return nFileLength; r<v_CFJ  
} $Q=$?>4U  
x~%\y  
? S8$5gA  
//保存下载信息(文件指针位置) =I7[L{+~Y  
private void write_nPos() TX&[;jsj  
{ ~6] )*y  
try{ =?^-P{:\?  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,Io0ZE>`V  
output.writeInt(nStartPos.length); Kjv2J;Xuh  
for(int i=0;i<nStartPos.length;i++) [@x  
{ t&3 8@p  
// output.writeLong(nPos); V@Ax}<$A  
output.writeLong(fileSplitterFetch.nStartPos); @kS|Jz$iY  
output.writeLong(fileSplitterFetch.nEndPos); w~ijD ^ g  
} 2UQN*_  
output.close(); ,=yOek}  
} W%=Zdm rv  
catch(IOException e){e.printStackTrace ();} "--/v. Cs  
catch(Exception e){e.printStackTrace ();} d4Ixuux<3  
} S3nB:$_-;  
 I.UjST  
C"k2<IE  
//读取保存的下载信息(文件指针位置) ~ 0av3G  
private void read_nPos() BF>T*Z-Ki  
{ g~eJ YS,  
try{ %s]U@Ku(a  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dP?nP(l  
int nCount = input.readInt(); nMLU-C!t  
nStartPos = new long[nCount]; Sb^add0dT  
nEndPos = new long[nCount]; `Yg7,{A\J  
for(int i=0;i<nStartPos.length;i++) \MF3CK@/  
{ RzMA\r;#  
nStartPos = input.readLong(); X #&(~1O  
nEndPos = input.readLong(); w 7Cne%J8  
} e og\pMv  
input.close(); CZF^Wxk  
} 7? +5%7-  
catch(IOException e){e.printStackTrace ();} ^tQPJ  
catch(Exception e){e.printStackTrace ();} 0kkRK*fp}x  
} '9f6ZAnYpQ  
/5&3WG&<u  
E*Pz <  
private void processErrorCode(int nErrorCode) | pF5`dX  
{ 7k.d|<mRv  
System.err.println("Error Code : " + nErrorCode); +Kxe ymwr2  
} &t[z  
N'htcC  
f34_?F<h  
//停止文件下载 ?f(pQy@V  
public void siteStop() ~JIywzcf8  
{ bXa %EMF  
bStop = true; =PI^X\if88  
for(int i=0;i<nStartPos.length;i++) >hHJ:5y  
fileSplitterFetch.splitterStop(); 3| GNi~  
,w,ENU0~f  
^qE<yn  
} xhw8#  
} cdd P T  
//负责部分文件的抓取 K(%dcUGDK>  
**FileSplitterFetch.java 5cPSv?x^F@  
*/ 0f_66`  
package NetFox; NEjPU#@c  
:(5]Z^  
er&uC4Y]a  
import java.io.*;  JsZAP  
import java.net.*; %@M00~-  
AGw1Pl8]K  
!%SdTaC{T  
public class FileSplitterFetch extends Thread { )6O\WB|  
%i;r]z-  
{JCSR2BB  
String sURL; //File URL v!WU |=u  
long nStartPos; //File Snippet Start Position M!;`(_2  
long nEndPos; //File Snippet End Position W;xW: -  
int nThreadID; //Thread's ID SS l8  
boolean bDownOver = false; //Downing is over "`gfy  
boolean bStop = false; //Stop identical )$2%&9b  
FileAccessI fileAccessI = null; //File Access interface ]#vvlM>/  
2+c>O%L  
M Ak-=?t  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .=.yZ  
{ {hkM*:U  
this.sURL = sURL; s!8J.hD'I  
this.nStartPos = nStart; W}#QKZ)MB  
this.nEndPos = nEnd; M=" WUe_  
nThreadID = id; > gA %MT  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )R [@G.  
} q/W{PBb-2k  
hP'~  
\'\N"g`Fr  
public void run() sR7{i  
{ l8hvq(,{  
while(nStartPos < nEndPos && !bStop) rCnV5Yb0O  
{ d/ 'A\"o+  
D=5t=4^H(  
7Va#{Y;Zy  
try{ n?<# {$  
URL url = new URL(sURL); a'*5PaXU@/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l<0[ K(  
httpConnection.setRequestProperty("User-Agent","NetFox"); C,sD?PcSi+  
String sProperty = "bytes="+nStartPos+"-"; 2n-Tpay0  
httpConnection.setRequestProperty("RANGE",sProperty); ,H#qgnp  
Utility.log(sProperty); SK2J`*  
F^%{ ;  
w@ gl  
InputStream input = httpConnection.getInputStream(); `? 9] '  
//logResponseHead(httpConnection); Z9 ;nC zHm  
qd#(`%_/  
]yj4~_&O  
byte[] b = new byte[1024]; #T gz,e9  
int nRead; )7Hon  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "NX m\`8  
{ hJ$C%1;  
nStartPos += fileAccessI.write(b,0,nRead); E :'  
//if(nThreadID == 1) Q G=-LXv:@  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,q'gG`M N  
} eMpEFY  
g%fJyk'  
B $ y44  
Utility.log("Thread " + nThreadID + " is over!"); R:pBbA7E  
bDownOver = true; qH {8n`  
//nPos = fileAccessI.write (b,0,nRead); -Y 6.?z  
} 8JjU 9#  
catch(Exception e){e.printStackTrace ();} Oo3qiw  
} _.Z&<.lJ  
} <'o'H  
%z!d4J75  
{"gyXDE1  
//打印回应的头信息 Xn ZX *Y]"  
public void logResponseHead(HttpURLConnection con) 4$q )e<-  
{ _x,-d|9b d  
for(int i=1;;i++)  }]n>A  
{ -Fok %iQ'5  
String header=con.getHeaderFieldKey(i); , $D&WH  
if(header!=null) BRSgB-Rr7  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XEgx#F ;F  
Utility.log(header+" : "+con.getHeaderField(header)); uV/HNzC  
else 2RSHB o  
break; 1"4nmw}  
} P"~qio-  
} _($-dJ {  
yuy+}]uB@  
\KnD"0KW   
public void splitterStop() %Zv(gI`A  
{ I 1VEm?CQ  
bStop = true; ?-.Ep0/  
} TYJnQ2m  
Ls$g-k%c@Q  
&[W3e3Asra  
} *k@0:a(>  
qqz,~EhC  
`1[Sv"  
/* sJHy=z0m  
**FileAccess.java wk@(CKQzI,  
*//文件访问(定位,写) H[_uVv;}6  
package NetFox; kj<D4)  
import java.io.*; x>8}|ou  
\{+nXn  
!rsqr32]  
public class FileAccessI implements Serializable{ hklO:,`  
nX.sh  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W:+2We@  
RandomAccessFile oSavedFile; ` HE:D2b  
long nPos; vElL.<..  
W_f"Gk  
4-}A'fTU8  
public FileAccessI() throws IOException utm+\/  
{ !+|N<`  
this("",0); (-Ct!aW|  
} L9unhx  
9^ *ZH1  
~a8G 5M  
public FileAccessI(String sName,long nPos) throws IOException 5S-o 2a  
{ SFk11  
oSavedFile = new RandomAccessFile(sName,"rw"); `9Q,=D+  
this.nPos = nPos; \Zz= 4 j  
oSavedFile.seek(nPos); 8a$jO+UvN  
} {GH`V}Ob  
Zh~Lm  
i37a}.;  
public synchronized int write(byte[] b,int nStart,int nLen) ]stLC; nI  
{ %6c*dy  
int n = -1; W|-N>,G  
try{ )r6SGlE[Y  
oSavedFile.write(b,nStart,nLen); {,  *Y  
n = nLen; 4k&O-70y4^  
} !Bd* L~D  
catch(IOException e) CXP $bt}  
{ Cp~3Jm3  
e.printStackTrace (); IIt^e#s&  
} (.XDf3   
b\|p  
"/K&qj  
return n; w<F;&' ;@h  
} )zLS,/pk^  
U37?P7i's  
hC 4X Y  
} tU2to V  
8|-mzb&  
t1{%FJ0F  
/* Qpv}N*v^  
**SiteInfoBean.java f$S QhK5`  
*/ +8vzkfr3It  
package NetFox; W.6 JnYLQ&  
>~wk  
3f2Hjk7,d  
public class SiteInfoBean { }vxH)U6$q  
(h>X:!  
sr($Bw  
private String sSiteURL; //Site's URL gc8PA_bFz  
private String sFilePath; //Saved File's Path ]gZ8b- 2O  
private String sFileName; //Saved File's Name DEwtP  
private int nSplitter; //Count of Splited Downloading File -.Pu5et4  
Wo WM  
T# _n-b>  
public SiteInfoBean() DGfQo5#  
{//nSplitter的缺省值为5 ,ZP3F+XKb  
//default value of nSplitter is 5 O\8|niW|  
this("","","",5); I&NpN~AU  
} !%\To(r[  
rs<&x(=Hv  
\gzwsT2&  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Rd1ku=  
{ hy&Hl  
sSiteURL= sURL; z9kX`M+  
sFilePath = sPath; <%#y^_  
sFileName = sName; q~dg   
this.nSplitter = nSpiltter; @G$<6CG\  
3;l>x/amk  
#M9D" <pn}  
} #m$%S%s  
K,,@',  
,JBw$ C  
public String getSSiteURL() Am?Hkh2  
{ 8OtUY}R  
return sSiteURL; WT!\X["FI$  
} |%cO"d^ri  
O2/w:zOg'  
aE cg_es  
public void setSSiteURL(String value) g*c\'~f;  
{ i7FR78^  
sSiteURL = value; ._8cJf.ae  
} = SJF \Z  
%iS]+Sa.K  
(*WZsfk>/<  
public String getSFilePath() wukos5  
{ ?G>TaTiK#  
return sFilePath; #bZ=R  
} JTB~nd>  
+e4<z%1  
CU`Oc>;*T  
public void setSFilePath(String value) u`Qcw|R+  
{ Vh2/Ls5  
sFilePath = value; yz$1qEII`q  
} HN~4-6[q  
Aag)c~D  
2hC$"Dfp  
public String getSFileName() ,p`b Wm  
{ R}6la.mQ  
return sFileName; Tocdh.H|  
} n_&)VF#n(  
%s :  
A-Pwi.$  
public void setSFileName(String value) W#_gvW  
{ 4NR5?s  
sFileName = value; 2xdJ(\JWM  
} P:-/3  
7Z~szD  
:h^UC~[h 3  
public int getNSplitter() ts\>_/  
{ S,9WMti4x  
return nSplitter; `&[:!U2]F  
} YJvT p~  
-&D6w9w  
f#Cdx"  
public void setNSplitter(int nCount) <\>ak7m  
{ 1nTaKK q  
nSplitter = nCount; p}|wO&4h  
} G/3lX^Z>  
} =}GyI_br;8  
sH,)e'0  
{ZEXlNPww  
/* Dlf=N$BL7d  
**Utility.java 5 ^J8<s@_  
*/ ZV4' |q  
package NetFox; 2OlC7X{  
{!Z_&i5  
K}3"KC  
public class Utility { t}+c/ C%b=  
xWb?i6)z&  
by<@Zwtf  
public Utility() .LcE^y[V  
{ '<D}5u7 2  
78~V/L;@S2  
PxD}j 2Kd  
} 9QZwUQ  
&0Zk3D4  
//线程睡眠 rWpfAE)!  
public static void sleep(int nSecond) ~EkGG .  
{ QGG(I7{-  
try{ `3P62M<  
Thread.sleep(nSecond); afq +;Sh  
} 6-}e-H  
catch(Exception e) G6mM6(Sr  
{ V="f)'S$  
e.printStackTrace (); Riuv@i^6K  
} E?D{/ k,zZ  
} ibUPd."W  
`|?$; )  
//日志 vbh#[,lh  
public static void log(String sMsg) {:OVBX  
{ r9*H-V$  
System.err.println(sMsg); S%#Mu|  
} ,8 ?*U]}  
P,=J"%a-  
*]?YvY  
public static void log(int sMsg) ]=<@G.[=  
{ Yx c >+mx  
System.err.println(sMsg); ^@"f%3  
} * xXc$T  
} %t.IxMY  
9gayu<J  
7B"aFnK;[J  
/* _tJURk%  
**TestMethod.java ]r5Xp#q2  
*/ Q 5TyS8  
package NetFox; RVy87_J1  
PP|xIAc  
a :AcCd)  
public class TestMethod { o|E(_ Y4d  
me\)JCZpb{  
I@v.Hqg+7  
public TestMethod() !gQ(1u|r  
{ ///xx/weblogic60b2_win.exe hmk5 1  
try{  :Xr3 3  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~,1X>N"  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cu|q &  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'Q,<_ L"  
fileFetch.start(); 8Wp1L0$B  
} CMUphS-KE  
catch(Exception e){e.printStackTrace ();} `&JA7UD>  
Py<vN!  
lR^Qm|  
} 6 VDF@V$E  
zxHfQ(  
s#49pDN  
public static void main(String[] args) PmTd+Gj$  
{ -W vAmi  
new TestMethod(); !\v3bOi&  
} ,aL"Wy(  
} v9kzMxs,  
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