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http断点续传简单实现(java)

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/* VM$n|[C~  
**SiteFileFetch.java N`W[Q>n  
*/ kyHli~Nr"  
package NetFox; Rzd`MIHDp  
import java.io.*; mi=mwN%UB  
import java.net.*; NzT &K7v  
`G$>T#Dq  
BA h'H&;V  
public class SiteFileFetch extends Thread { ei5YxV6I  
}5+^  
H~FI@Cf$L  
SiteInfoBean siteInfoBean = null; //文件信息Bean >+{WiZ`  
long[] nStartPos; //开始位置 Ksx-Y"  
long[] nEndPos; //结束位置 S>oEk3zlw  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 QoYEWXT|g  
long nFileLength; //文件长度 pA!-spgX  
boolean bFirst = true; //是否第一次取文件 cKVFykwM  
boolean bStop = false; //停止标志 e\6H.9=  
File tmpFile; //文件下载的临时信息 ^*AI19w!Ys  
DataOutputStream output; //输出到文件的输出流 ]?}>D?5  
VlV X  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) h%EeU 3  
public SiteFileFetch(SiteInfoBean bean) throws IOException S70#_{  
{ [QnN1k  
siteInfoBean = bean; KZ5%q.  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); }PI:O%N;  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");  I0mp[6  
if(tmpFile.exists ()) W]po RTJ:  
{ `0Udg,KOs  
bFirst = false; nI3p`N8j*  
read_nPos(); *'?ZG/ (  
} Kg 6J:HD49  
else s,Gl{  
{ ek&~A0k_o  
nStartPos = new long[bean.getNSplitter()]; |.@!CqJ  
nEndPos = new long[bean.getNSplitter()]; T1C_L?L  
} :Q`Of}#  
Q+Bl1xl  
E ASnh   
JSB+g;  
} H@(O{ 9Yl;  
7Yg1z%%U  
> 'R{,1# U  
public void run() 5|rBb[  
{ n.@HT"  
//获得文件长度 |[rn/  
//分割文件 #&.Znk:@.f  
//实例FileSplitterFetch t oA}0MI(:  
//启动FileSplitterFetch线程 y_9\07va<  
//等待子线程返回 Z=&|__ +d  
try{ "lt<$.  
if(bFirst) |" }rdOV)  
{ iDDJJ>F26  
nFileLength = getFileSize(); sRt7.fe  
if(nFileLength == -1) TJv .T2|  
{ `"=Hk@E  
System.err.println("File Length is not known!"); %6q82}#`  
} ]fajj\  
else if(nFileLength == -2) $2uC%er"H  
{ myj/93p}`b  
System.err.println("File is not access!"); 20}HTV{v  
} >*EZZ\eU!  
else $q\"d?n  
{ kEh\@x[  
for(int i=0;i<nStartPos.length;i++) 4ior  
{ ovp/DM  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Qhj']>#g  
} 1i#y>fUj  
for(int i=0;i<nEndPos.length-1;i++) 0PkX-.  
{ i`+w.zJOH8  
nEndPos = nStartPos[i+1]; qiet<F  
} 9JdJn>  
nEndPos[nEndPos.length-1] = nFileLength; k[8F: T-  
} {H/%2  
} I7_8oq\3D  
k<1i.rh  
2{j$1EdI@-  
//启动子线程 L]MWdD  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K^!#;,0  
for(int i=0;i<nStartPos.length;i++) $]LS!@ Rm  
{ 0m3hL~0(a  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zv}F?4T~:  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), brTNwRze  
nStartPos,nEndPos,i); H|aFs.SEQ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b"$?(Y  
fileSplitterFetch.start(); _o9axBJs  
} ?jR#txR  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `i.fm1I]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W_@ b. 1  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @A6iY  
nEndPos = " + nFileLength); s={>{,E  
// fileSplitterFetch[nPos.length-1].start(); `!cdxKLR  
#;8)UNc)}  
_jX,1+M  
//等待子线程结束 `LoRudf_`  
//int count = 0; 5=V"tQ&d9U  
//是否结束while循环 9<3(  QR  
boolean breakWhile = false; Tbm ~@k(C  
Osz=OO{  
#[bosb!R  
while(!bStop) )bg|l?  
{ M IIa8 ;  
write_nPos(); oO;L l?~  
Utility.sleep(500); 3!9JXq%Hl  
breakWhile = true; M_!]9#:K7  
d21thV ,S  
2D%2k  
for(int i=0;i<nStartPos.length;i++) BP j?l  
{ ~j[?3E4L}  
if(!fileSplitterFetch.bDownOver) G$a@}9V  
{ Y*@7/2,  
breakWhile = false; fK:4jl-r  
break; (8 7wWhH  
} z#!<[**&  
} Aq(cgTNW  
if(breakWhile) I'IFBVhaYn  
break; GDCp@%xW  
ga|<S@u?}  
%( OP  [  
//count++; n=j) M  
//if(count>4) K^o$uUBe  
// siteStop(); IwYfs]-  
} zx<t{e7  
gH7  +#/  
\j!/l f)  
System.err.println("文件下载结束!"); 0m1V@ 3]7>  
} _v#pu Fy  
catch(Exception e){e.printStackTrace ();} egsP\ '  
} & PXT$x[i  
I+Fy)=DO9  
 p[&J l  
//获得文件长度 S8qg"YR  
public long getFileSize() } Nn+Ny  
{ 8/p ]'BLf  
int nFileLength = -1; =xkaF)AW&v  
try{ PW@ :fM:q  
URL url = new URL(siteInfoBean.getSSiteURL()); [>`.,k  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W'9{2h6u(  
httpConnection.setRequestProperty("User-Agent","NetFox"); TAh'u|{u2  
H,c1&hb/w  
*-*V>ntvT$  
int responseCode=httpConnection.getResponseCode(); _886>^b@  
if(responseCode>=400) RCfeIHL  
{ >A{e,&  
processErrorCode(responseCode); Z?S?O#FED  
return -2; //-2 represent access is error Ru d9l.n  
}  R<1%Gdz  
waz5+l28  
d(}? \|  
String sHeader; Ag T)J  
Mh3.GpS  
Wj3i*x$  
for(int i=1;;i++) [[_>D M  
{ Z[[*:9rY|  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '9]?jkl  
//Utility.log(in.readLine()); DCa[?|Y  
sHeader=httpConnection.getHeaderFieldKey(i); i5(qJ/u  
if(sHeader!=null) .qe+"$K'n  
{ 3VU4E|s>  
if(sHeader.equals("Content-Length")) #:=c)[G8  
{ IJ+}  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9Znc|<  
break; b`%u}^B {  
} < - sr&  
} Zl%)#=kO  
else V %[t'uh  
break; fqbWD)L]  
} 0X99D2c  
} jSBz),.XU}  
catch(IOException e){e.printStackTrace ();} { #B/4  
catch(Exception e){e.printStackTrace ();} prM)t8SE  
\aPH_sf,  
A%EhRAy  
Utility.log(nFileLength); 5G6 Pp7[  
+EA ")T<l  
F%zMhX'AG  
return nFileLength; [,st: Y  
} 3W ]zLUn  
uN?Lz1W\;  
Hwd^C 2v  
//保存下载信息(文件指针位置) V O1   
private void write_nPos() }x$@j  
{ dR i6  
try{ x xzUey  
output = new DataOutputStream(new FileOutputStream(tmpFile)); f }r \  
output.writeInt(nStartPos.length); vC&0UNe$  
for(int i=0;i<nStartPos.length;i++) 1r4NP  
{ **-rPonM[  
// output.writeLong(nPos); UazK0{t<f  
output.writeLong(fileSplitterFetch.nStartPos); RJ3uu NK7  
output.writeLong(fileSplitterFetch.nEndPos); 8 |= c3Z  
} =KO]w9+\  
output.close(); @fA| y  
} `B&E?x  
catch(IOException e){e.printStackTrace ();}  [A,!3BN  
catch(Exception e){e.printStackTrace ();} /qKor;x  
} VPYcA>-%u  
gCYe ^KJ  
|H8C4^1Rq  
//读取保存的下载信息(文件指针位置) [V /f{y~ {  
private void read_nPos() )6"p@1\u  
{ BGVnL}0  
try{ GLub5GrxR  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7H6Ge-u  
int nCount = input.readInt(); <:(;#&<  
nStartPos = new long[nCount]; d|87;;X|u  
nEndPos = new long[nCount]; VJA/d2Oys  
for(int i=0;i<nStartPos.length;i++) AEf[:]i]  
{ l' Li!u  
nStartPos = input.readLong(); ' rXf  
nEndPos = input.readLong(); f3vl=EA4|  
} z+M{z r  
input.close(); l`6.(6  
} 5`}za-  
catch(IOException e){e.printStackTrace ();} O)R}|  
catch(Exception e){e.printStackTrace ();} Y]~-S  
} ;j~%11  
+p _?ekV\  
EBWM8~Nm#  
private void processErrorCode(int nErrorCode) _8SB+s*  
{ {{bwmNv"  
System.err.println("Error Code : " + nErrorCode); IrRe6nf@K  
} F `F|.TX  
Y1AZ%{^0a  
7uUq+dp  
//停止文件下载 7r3CO<fb  
public void siteStop() r4K_Wp  
{ @D["#pe,}  
bStop = true;  EAr;  
for(int i=0;i<nStartPos.length;i++) ?|oN}y"i  
fileSplitterFetch.splitterStop(); 1QhQ#`$<1  
]p4?nT@]  
S+Ia2O)BA  
} ^v5]Aq~X  
} ON{a'H  
//负责部分文件的抓取 $B9?>a|{A  
**FileSplitterFetch.java usKP9[T$  
*/ DIP%*b#l$\  
package NetFox; s9Tn|Pm+!\  
?|NsaW  
A3HN Mz  
import java.io.*; | h"$  
import java.net.*; U7fNA7#x"  
O\oRM2^u}  
dA2@PKK  
public class FileSplitterFetch extends Thread { Gys-Im6>~@  
xz} CqPJ#  
A#Ga!a  
String sURL; //File URL V\n!?1{kdF  
long nStartPos; //File Snippet Start Position uARkf'  
long nEndPos; //File Snippet End Position N*PJ m6-  
int nThreadID; //Thread's ID 3,!IV"_  
boolean bDownOver = false; //Downing is over vN]_/T+  
boolean bStop = false; //Stop identical R:'&>.AUw  
FileAccessI fileAccessI = null; //File Access interface  D5Jg(-  
V2;Nv\J\  
Az(,Q$"|5  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gDw(_KC  
{ &_@M 6[-  
this.sURL = sURL; 7^@ 1cA=S  
this.nStartPos = nStart; #PC*l\ )  
this.nEndPos = nEnd; ())_4 <  
nThreadID = id; !Dc;R+Ir0!  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I"8Z'<|/\q  
} ~rq:I<5  
Xmb##:  
Jp8,s%  
public void run() I@Y k &aU  
{ B"88 .U}$  
while(nStartPos < nEndPos && !bStop) iYdg1  
{ ;$]a.9 -  
SN7_^F  
/r&4< @  
try{ -J'ked  
URL url = new URL(sURL); pp#!sRUKPV  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %k"hzjXAw  
httpConnection.setRequestProperty("User-Agent","NetFox"); wT3D9N.  
String sProperty = "bytes="+nStartPos+"-"; S,'ekWVD  
httpConnection.setRequestProperty("RANGE",sProperty); c8_,S[W  
Utility.log(sProperty); T gLr4Ex  
?!c7Zx,(  
o5+7Lt]  
InputStream input = httpConnection.getInputStream(); $QT% -9&  
//logResponseHead(httpConnection); E+ XR[p  
7bVKH[  
u#V;  
byte[] b = new byte[1024]; gH"a MEC  
int nRead; zT!.5qd  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V sL*&Fk  
{ )$pqe|,  
nStartPos += fileAccessI.write(b,0,nRead); P;X0L{u0H  
//if(nThreadID == 1) 6%o@!|=I  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tp ky  
} E=bZ4 /  
={p<|8`"  
bx7hQzoX=b  
Utility.log("Thread " + nThreadID + " is over!"); 5yW}#W>  
bDownOver = true; l r~>!O  
//nPos = fileAccessI.write (b,0,nRead); >r4BI}8SK<  
} u2':~h?l  
catch(Exception e){e.printStackTrace ();} c*(=Glzn  
} V6Of(;r  
} b ts*qx&)  
PKGqu,J,  
)1YGWr;ykS  
//打印回应的头信息 plzwk>b_  
public void logResponseHead(HttpURLConnection con) Hg\H>Z  
{ )wEXCXr!  
for(int i=1;;i++) AGx(IK/_  
{ 0G'v4Vj0'  
String header=con.getHeaderFieldKey(i); sAK&^g  
if(header!=null) dJb7d`  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l{kacfk#  
Utility.log(header+" : "+con.getHeaderField(header)); i4SWFa``  
else M%!j\}2A  
break; daf-B-  
} `"xzC $  
} 2@&"*1(Xu  
0'zjPE#  
~PN[ #e]  
public void splitterStop() idS+&:'  
{ )Dcee@/7S  
bStop = true; Ghe@m6|D  
} \pI ,6$'  
3m~3l d  
+\vN#xDz  
} $ Fy)+<  
Aq$o&t  
[2 Rz8e^  
/* "/hLZl  
**FileAccess.java u b@'(*  
*//文件访问(定位,写) %7Gq#rq  
package NetFox; n*~#]%4  
import java.io.*; v=IcVHuf  
h}+Gz={Q^  
tK\$LZ  
public class FileAccessI implements Serializable{ (d[JMO^@8  
E/d\ebX|  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Hjy4tA7,l  
RandomAccessFile oSavedFile; xf qu=z8X  
long nPos; BK.RYSN  
"(a}}q 9-  
)9!J $q  
public FileAccessI() throws IOException Y~OyoNu2  
{ 7l'1  
this("",0); ?CpM.{{s  
} NL"w#kTc()  
;tZ8Sh)  
368H6 Jj  
public FileAccessI(String sName,long nPos) throws IOException S~y.>X3"P  
{ pTYV@5|  
oSavedFile = new RandomAccessFile(sName,"rw"); Q0""wR q'  
this.nPos = nPos; Mi[,-8Sk  
oSavedFile.seek(nPos); ^687U,+  
} T zHR  
r+MqjdXG  
:O*62olC5  
public synchronized int write(byte[] b,int nStart,int nLen) Tz/[P:O3  
{ 7{[i)  
int n = -1; .R@euIva  
try{ 3TKl  
oSavedFile.write(b,nStart,nLen); EmV ZqW  
n = nLen; 9lX+?m~ ~  
} (=s%>lW|  
catch(IOException e) %S%0/  
{ ?zK>[L  
e.printStackTrace (); g^k=z:n3,  
}  Z Mf,3  
O$Dj_R#  
J]&nZud`  
return n; 2u} ns8wn  
} ^cojETOv  
/5:qS\Zl  
@])}+4D(S  
} \@j3/!=,n%  
&$pA,Gjin\  
i]zTY\gw8M  
/* uU8L93  
**SiteInfoBean.java ,j[1!*Z_[  
*/ `$r?^|T  
package NetFox; ,Q8h#0z r  
w8-L2)Q}I  
RSF@Oo{  
public class SiteInfoBean { CSE!Abg  
 w"h'rw  
m^a0JR}u9  
private String sSiteURL; //Site's URL TfA;4 ^  
private String sFilePath; //Saved File's Path &_Gu'A({J  
private String sFileName; //Saved File's Name  #U/L8  
private int nSplitter; //Count of Splited Downloading File @<p9 O0  
3T@`V FbE  
<kWNx.eci  
public SiteInfoBean() I,?!NzB  
{//nSplitter的缺省值为5 7FP @ vng  
//default value of nSplitter is 5 +|spC  
this("","","",5); ; 5!8LmZ0#  
} ;:ocU?  
l8N5}!N  
x>[ gShAV!  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A@I3:V  
{ j!?bE3r~  
sSiteURL= sURL; $b"Ex>  
sFilePath = sPath; hmtDw,j  
sFileName = sName; ! 9=Y(rb  
this.nSplitter = nSpiltter; T;B/ Wm!x  
:J6FI6  
}+ TA+;  
} uulzJbV,K  
)Z@hk]@?_[  
Th5}?j7  
public String getSSiteURL() ]\J(  
{ E&|EokSyN  
return sSiteURL; ?} U l(  
} eLop}*k  
.+CMm5T  
>tV:QP]Y  
public void setSSiteURL(String value) 78u=Jz6  
{ /d1V&Lj  
sSiteURL = value; _." X# }W  
} V4x6,*)e  
*|/kKvN  
H AMps[D[  
public String getSFilePath() uGS^*W$  
{ >qynd'eToR  
return sFilePath; l)91v"vJ  
} VV=6v;u`  
]hA]o7 k  
LfG$?<}hR  
public void setSFilePath(String value) \!'K#%]9  
{ +Ram%"Zwh  
sFilePath = value; /Oa.@53tK6  
} %'[ pucEF  
e#{l  
U\",!S~<  
public String getSFileName() bn"z&g   
{ ~1.~4~um  
return sFileName; ; WsV.n  
} f n\&%`U  
Zq"wq[GCN  
A/*h[N+2!  
public void setSFileName(String value) *Ja,3Qq  
{ 0'tm.,  
sFileName = value; n(el  
} :Nw7!fd  
#+PfrS=  
82Nw 6om6i  
public int getNSplitter() 08E,U  
{ 5%(xZ  6  
return nSplitter; B?<Z(d7  
} OL$^7FB  
fsVr<m  
u&ozc  
public void setNSplitter(int nCount) bR? $a+a)  
{ vke]VXU9z  
nSplitter = nCount; d`4@aoM  
} rwep e5  
} FuZLE%gP  
JQWW's}  
v D4<G{  
/* d9uT*5f  
**Utility.java 9w,u4q  
*/  Ry iS  
package NetFox; p` LPO  
cK+y3`.0  
de?lO ;8  
public class Utility { oq}Q2[.b  
vH9Gf  
t>>\U X  
public Utility() +S>}<OE  
{ i3\6*$Ug  
9k>=y n  
 |{@_J  
} -)ag9{*  
H>2f M^  
//线程睡眠 7Ke#sW.HN  
public static void sleep(int nSecond) Ty>g:#bogI  
{ V{G9E  
try{ vdN0YCXG  
Thread.sleep(nSecond); 66~]7w  
} Dhe ]f#d  
catch(Exception e) -,#LTW<.  
{ z;En Ay{9  
e.printStackTrace (); l<mEGKB#  
} k@= LR  
} #5.L%F  
:,(ZMx\  
//日志 d[.JEgU  
public static void log(String sMsg) (KxL*gB  
{ 0Ku%9wh-  
System.err.println(sMsg); HR83{B21  
} ZM%z"hO9R  
O6pL )6d  
nob^ I5?  
public static void log(int sMsg) [,fdNxc8  
{ )\TI^%s  
System.err.println(sMsg); ku}I; k |  
} l6Q75i)eF  
} #GHLF  
]xIfgSq  
[#R<Z+c  
/* p@7[w@B\c  
**TestMethod.java UPkD^D,  
*/ .%4{zaB  
package NetFox; R'q:Fc  
;Q =EI%_tv  
j\SW~}d9  
public class TestMethod { yxa~R z/  
vYNh0)$%F  
q:1_D>  
public TestMethod()  }[<eg>9#  
{ ///xx/weblogic60b2_win.exe JDzk v%E^  
try{ vK\;CSk  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RZ[r XV5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1Bz'$u;  
SiteFileFetch fileFetch = new SiteFileFetch(bean); SdfrLdi}Y  
fileFetch.start(); i%~4>k  
} -vfV;+3  
catch(Exception e){e.printStackTrace ();} ~4mgYzOmD`  
fx QN  
j}?O  
} u= K?K  
3a4 ]{  
{O,Cc$_  
public static void main(String[] args) %Iv0<oU  
{ mdOF0b%-]  
new TestMethod(); '* +]&~b  
} k:w\4Oqd  
} t$=0  C  
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