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http断点续传简单实现(java)

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/* :HRJ49a  
**SiteFileFetch.java N6$pOQ  
*/ IO`.]iG  
package NetFox; >f19P+  
import java.io.*; 57)S"  
import java.net.*; s7SW4ff1  
$uawQf+S  
8N!E`{W  
public class SiteFileFetch extends Thread { `.Y["f 1B  
,$mnD@)  
G|Ic6Sd  
SiteInfoBean siteInfoBean = null; //文件信息Bean c&3 ]%urL  
long[] nStartPos; //开始位置 vML01SAi  
long[] nEndPos; //结束位置 ,2[laJ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Tm_AoZH  
long nFileLength; //文件长度 sZPPS&KoP3  
boolean bFirst = true; //是否第一次取文件 /lm;.7_J+  
boolean bStop = false; //停止标志 zVZZdG~8  
File tmpFile; //文件下载的临时信息 Jj|HeZ1C f  
DataOutputStream output; //输出到文件的输出流 #wNksh/J^  
q*Yh_IT.I  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) AASw^A3p  
public SiteFileFetch(SiteInfoBean bean) throws IOException z* YkD"]B  
{ A<r@,*(g  
siteInfoBean = bean; AR]y p{NS  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); II)\rVP5  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); PLKp<kg  
if(tmpFile.exists ()) *ZKI02M  
{ WHqp7NPl  
bFirst = false; ^T)HRT-k  
read_nPos(); 7tfMD(Q]e/  
} 5 r"`c  
else 0MF[e3)a  
{ r{$ip"f  
nStartPos = new long[bean.getNSplitter()]; bAeC=?U  
nEndPos = new long[bean.getNSplitter()]; F5wCl2I  
} _$NFeqLww  
j@v*q\X&  
IaH8#3+a  
$s4rG=q  
} x<"1T w5e  
syA*!Up  
CVo@zr$  
public void run() 3)T'&HKQ  
{ *O#%hTYq  
//获得文件长度 kUmrJBh$  
//分割文件 \kvd;T#t6  
//实例FileSplitterFetch rm;'/l8Y-E  
//启动FileSplitterFetch线程 7qA0bUee5  
//等待子线程返回 cTHSPr?<  
try{ ,_r"=>?@  
if(bFirst) wW1aG  
{ gV):3mWC  
nFileLength = getFileSize(); KIC5U50J  
if(nFileLength == -1) d `>M-:dF  
{  &xgMqv2/  
System.err.println("File Length is not known!"); s-}|_g.Pt  
} s&iM.[k  
else if(nFileLength == -2) bA@!0,m  
{ tU >wRw=d  
System.err.println("File is not access!"); n&D<l '4  
} Z%y>q|:  
else 2^bq4c4J  
{ _Buwz_[&  
for(int i=0;i<nStartPos.length;i++) \acJ9N  
{ dD?1te  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ';hU&D;s  
} 8E&}+DR?  
for(int i=0;i<nEndPos.length-1;i++) o=_:g >5  
{ T,@.RF  
nEndPos = nStartPos[i+1]; Yew n  
} cNtGjLpx;  
nEndPos[nEndPos.length-1] = nFileLength; L$cNxz0$  
} & 1p\.Y  
} Ds9pXgU( Z  
]{{A/ j\  
N#Y%+1  
//启动子线程 h=.|!u  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nW3-)Q89  
for(int i=0;i<nStartPos.length;i++) pzbR.L}'D  
{ 8V>j-C  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (8TB*BhQ_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 53J!iNnXT6  
nStartPos,nEndPos,i); WW{5[;LYiB  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o%i^t4J$e  
fileSplitterFetch.start(); PBbJfm  
} yQ}$G ,x  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7*^-3Tt83  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Bq.@CxK  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T1m"1Q  
nEndPos = " + nFileLength); "=@b>d6U+  
// fileSplitterFetch[nPos.length-1].start(); n.ZLR=P4  
8i!AJF9IQ}  
L{jJDd  
//等待子线程结束 E0'+]"B  
//int count = 0; =@AWw:!:,  
//是否结束while循环 V&;1n  
boolean breakWhile = false; J 05@SG':  
Yz=(zj  
OXe+=Lp<  
while(!bStop) [9(tIb!x  
{ gELku .  
write_nPos(); N:GSfM@g  
Utility.sleep(500); K#rfQ0QK/!  
breakWhile = true; OSQZ5:g|  
S<rdPS*P  
{YC!pDG  
for(int i=0;i<nStartPos.length;i++) Ehi)n)HhG"  
{ f.JZ[+  
if(!fileSplitterFetch.bDownOver) mE'y$5ZxY  
{ 0?KXQD  
breakWhile = false; -G e5gQ=  
break; rZ2X$FO@  
} FRd!UqMXY  
} (+6 8s9XS7  
if(breakWhile) px %xoY  
break; 26PUO$&b.  
^E\{&kaUp  
Qz\yoI8JA,  
//count++; ( NWT/yBx  
//if(count>4) L`;p.L Bs_  
// siteStop(); 3XF.$=@  
} I_6NY,dF  
,yus44w[  
S-}MS"  
System.err.println("文件下载结束!"); fOJ 0#^Z  
} %tul(Z~<1  
catch(Exception e){e.printStackTrace ();} [Oen{c9 A  
} %KHO}gad1  
o(w!x!["  
k4fc 5P  
//获得文件长度 .) uUpY%K^  
public long getFileSize() BZejqDr*  
{ |z\5Ik!fF]  
int nFileLength = -1; F-[zuYGp  
try{ 7[h_"@_A7  
URL url = new URL(siteInfoBean.getSSiteURL()); XK??5'&{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &[:MTK?x!  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;Pf |\q  
[ -"o5!0<  
gNF8&T  
int responseCode=httpConnection.getResponseCode(); F1)B-wW  
if(responseCode>=400) =M'M/vKD  
{ PLU8:H@X  
processErrorCode(responseCode); +^ a9i5  
return -2; //-2 represent access is error bP\0S@1YL  
} A]ZCQ49  
QA>(}u\+  
D X GClH  
String sHeader; VN[C%C  
9qN4f8R  
~,+n_KST;  
for(int i=1;;i++) YL-/z4g  
{ Z?X0:WK  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _OV\W'RrA  
//Utility.log(in.readLine()); w}No ^.I*4  
sHeader=httpConnection.getHeaderFieldKey(i); u$ C@0d  
if(sHeader!=null) N`XJA-DE  
{ 56gpAc  
if(sHeader.equals("Content-Length")) g?` g+:nug  
{ .w2QiJ  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i)9}+M 5  
break; ;,P-2\V/  
} arJ4^  d  
} :W]?6=  
else L1=3_fO  
break; &7Frg`B&:  
} AzAD76iNv  
} \$:KfN>WY  
catch(IOException e){e.printStackTrace ();} Fx,08  
catch(Exception e){e.printStackTrace ();} ~f=~tN)hZ  
jJFWPD ] u  
<i{O\K]9  
Utility.log(nFileLength); N<lejZ}!q  
w1HE^ /  
rt">xVl  
return nFileLength; 7pMl:\  
} 3 i<,#FaL  
?xEQ'(UBQ  
/~3~Xc ~=p  
//保存下载信息(文件指针位置) !Ic;;<  
private void write_nPos() 4;"^1 $  
{ r_C|gfIP  
try{ 0\v98g<[+  
output = new DataOutputStream(new FileOutputStream(tmpFile)); )006\W|t9  
output.writeInt(nStartPos.length); 1Vq]4_09g1  
for(int i=0;i<nStartPos.length;i++) lOIBX@K E  
{ mr:;Wwd  
// output.writeLong(nPos); Yhdt"@;..  
output.writeLong(fileSplitterFetch.nStartPos); 1HQh%dZZ  
output.writeLong(fileSplitterFetch.nEndPos); _y#omEx  
} HT]W2^k  
output.close(); H`u8}{7  
} ,M2u (9  
catch(IOException e){e.printStackTrace ();} A4LGF  
catch(Exception e){e.printStackTrace ();} Z$ qFjWp  
} 3t<XbHF9  
U'^AJ2L8  
+5J"G/f  
//读取保存的下载信息(文件指针位置) 'J^ M`/  
private void read_nPos() bwh7.lDAl  
{ kN3T/96  
try{ tP; &$y.8  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )|;*[S4  
int nCount = input.readInt(); ` nBCCz'Y!  
nStartPos = new long[nCount]; `$og]Dn;  
nEndPos = new long[nCount]; zNSix!F  
for(int i=0;i<nStartPos.length;i++) iVq4&X_x  
{ ").MU[q%Y  
nStartPos = input.readLong(); *M5 : \+  
nEndPos = input.readLong(); A ?"(5da.  
} _&S?uz m  
input.close(); ;>^oe:@  
} R=M"g|U6  
catch(IOException e){e.printStackTrace ();} 0kN;SSX!  
catch(Exception e){e.printStackTrace ();} JA W}]:jC  
} blxAy  
.G[y^w)w}  
,#3}TDC  
private void processErrorCode(int nErrorCode) kp3(/`xP  
{ _\E{T5  
System.err.println("Error Code : " + nErrorCode); /dTy%hZC}  
} `5 py6,  
(]7*Kq  
d,=Kv  
//停止文件下载 /lAB  
public void siteStop() ?pgdj|"a  
{ w:Ui_-4*>  
bStop = true; CU =}]Y  
for(int i=0;i<nStartPos.length;i++) P.*J'q 28  
fileSplitterFetch.splitterStop(); +|.}oL^}G  
!_GY\@}  
 }* iag\  
} ?wE@9 g A  
} \m-fLX  
//负责部分文件的抓取 ~~:w^(s9  
**FileSplitterFetch.java a%*l]S0z"  
*/ ~ILig}I  
package NetFox; wu?ahNb.`Y  
AH`n  
@rs(`4QEh  
import java.io.*; Z J(/cD  
import java.net.*; Z=%+U _,  
* d6[k Y  
xGbr>OqkTX  
public class FileSplitterFetch extends Thread { "%~\kJ(G  
V~LZ%NZ8  
eeIh }t>[  
String sURL; //File URL x4v@Kk/  
long nStartPos; //File Snippet Start Position w+Ve T@  
long nEndPos; //File Snippet End Position }HS:3Dt  
int nThreadID; //Thread's ID ?]gZg[  
boolean bDownOver = false; //Downing is over Ke[doQ#c  
boolean bStop = false; //Stop identical .(o]d{ '-}  
FileAccessI fileAccessI = null; //File Access interface  f])?Gw  
ZK5(_qW&i  
3oX%tx  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H"(:6 `  
{ MhC74G  
this.sURL = sURL; 0?uX}8w  
this.nStartPos = nStart; XfA3Ez,}  
this.nEndPos = nEnd; zM6 yUEg  
nThreadID = id; 70_T;K6  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }GvoQ#N  
} G%)?jg@EA  
U -~%-gFC  
*nNzhcuR  
public void run() -oq!zi4:  
{ A2'   
while(nStartPos < nEndPos && !bStop) !f_GR Pj'  
{ dJ\6m!Mp  
,oe e'  
PJj{5,#@3  
try{ =/=x"q+X  
URL url = new URL(sURL); Ab7hW(/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); / uI/8>p(  
httpConnection.setRequestProperty("User-Agent","NetFox"); oR}ir  
String sProperty = "bytes="+nStartPos+"-"; ulFU(%&  
httpConnection.setRequestProperty("RANGE",sProperty); o;Ijv\Em  
Utility.log(sProperty); 4W8rb'B!Ay  
|Hn[XRsf  
q! W ~>c!  
InputStream input = httpConnection.getInputStream(); 1!8*mk_R{  
//logResponseHead(httpConnection); 20m6-rkI<}  
P Y +~,T2  
"@B! 5s0  
byte[] b = new byte[1024]; Wm:3_C +j  
int nRead; Pb?H cg  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mm$D1=h{|  
{ YVVX7hB  
nStartPos += fileAccessI.write(b,0,nRead); 7ka^y k@Q  
//if(nThreadID == 1) i]GBu  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !s,<h U#  
} c 5P52_@  
R7*Jb-;$!  
Wq)'0U;{$  
Utility.log("Thread " + nThreadID + " is over!"); 1=#r$H  
bDownOver = true; $oE 4q6b  
//nPos = fileAccessI.write (b,0,nRead); ~l!(I-'?g  
} o^RdVSkU;  
catch(Exception e){e.printStackTrace ();} <mHptgd,  
} L1BpkB  
} LoHWkNZ5:  
uuj"Er31  
gT @YG;  
//打印回应的头信息 IcL3.(!]l  
public void logResponseHead(HttpURLConnection con) Wy#`*h,  
{ ->wY|7  
for(int i=1;;i++) ;]fpdu{  
{ hgj#VY$B  
String header=con.getHeaderFieldKey(i); j>&n5?  
if(header!=null) 567ot|cc  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5!#"8|oY  
Utility.log(header+" : "+con.getHeaderField(header)); el!Bi>b9c!  
else w|WZEu:0|  
break; A`(p6 H"s  
} V$ 38  
} *wt yyP@  
/iif@5lw{  
+Smv<^bW  
public void splitterStop() |}Mkn4  
{ sxL;o >{  
bStop = true; 4\pA^%73  
} d1e'!y}R5  
&o"Hb=k<  
}=A6Jv(j  
} QXJD' c  
ZC"6B(d  
]+0-$t7Y  
/* +^YV>;  
**FileAccess.java _if&a'  
*//文件访问(定位,写) ?y<n^`  
package NetFox; XeDU ,  
import java.io.*; I#eIm3Y?  
R,Zuy( g  
 hPr  
public class FileAccessI implements Serializable{ #!#V!^ o  
d\;M F  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dMGu9k~u  
RandomAccessFile oSavedFile; 3\=8tg p  
long nPos; HKOJkbVZ2^  
vlIdi@V  
^'EEry  
public FileAccessI() throws IOException ^\N2 Iu>6  
{ D\({]oj]  
this("",0); >[|:cz  
} R5]R pW=G  
%h|z)  
#PXl*~PrQ/  
public FileAccessI(String sName,long nPos) throws IOException |D]jdd@!a2  
{ q 4 Ye  
oSavedFile = new RandomAccessFile(sName,"rw"); |<y[gj4`T/  
this.nPos = nPos; KH pxWq  
oSavedFile.seek(nPos); KXw \N!  
} um ,/^2A  
N)poe2[  
/2'\ya4B  
public synchronized int write(byte[] b,int nStart,int nLen) nr&G4t+%Hv  
{ z*yN*M6t  
int n = -1; u"T5m  
try{ 9k7|B>LT  
oSavedFile.write(b,nStart,nLen); e}[$ =  
n = nLen; }QJE9;<e  
} Slv}6at5  
catch(IOException e) ~fCD#D2KU  
{ -HoPECe  
e.printStackTrace (); J=zZGd%  
} 8w2+t>?  
?9?0M A<[i  
X0vkdNgW  
return n; &)s A(  
} S NK+U"Q  
AZl=w`;/O%  
Q|5wz]!5Y(  
} (|U+(~PJ  
Y}1|/6eJ  
&OI=r vDmo  
/* .\U+`>4av  
**SiteInfoBean.java ZLL0 6p   
*/ Nq*\{rb  
package NetFox; qk_ s"}sS  
bO2$0!=I  
k9^P#l@p  
public class SiteInfoBean { $%1[<}<  
Q8:u1$}  
U +mx@C_  
private String sSiteURL; //Site's URL ' J-(v  
private String sFilePath; //Saved File's Path _|A)ueY  
private String sFileName; //Saved File's Name Z]SCIU @+  
private int nSplitter; //Count of Splited Downloading File Nm,v E7M  
<[~x]-  
Hlz4f+#I  
public SiteInfoBean() +!_^MBkk  
{//nSplitter的缺省值为5 :eIB K  
//default value of nSplitter is 5 !5A nr  
this("","","",5); W{-N,?z  
} f2{4Y)  
}WCz*v1Wq  
(Mtc&+n{  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~Zj?%4  
{ h+Q ==  
sSiteURL= sURL; 0A1l"$_|  
sFilePath = sPath; kN}.[enI~  
sFileName = sName; l>=c]  
this.nSplitter = nSpiltter; R8],}6,;E}  
zb;' }l;+  
4&y_+  
} r`S]`&#}(  
j ^_ G  
Szg<;._J  
public String getSSiteURL() #Jm_~k  
{ '|]zBpz  
return sSiteURL; |fw+{f  
} 5n9F\T5  
sWX   
3}h&/KN{  
public void setSSiteURL(String value) a#raUF7e  
{ 'm2,7]  
sSiteURL = value; *K+*0_  
} G %#us3x  
F5MWxAS,>  
s#d# *pgzh  
public String getSFilePath() ZnJnjW PQ  
{ x(t} H8q  
return sFilePath; '6xn!dK  
} ^ MddfBwk  
=} vG|  
x%(!+  
public void setSFilePath(String value) ikxSWO_Y=  
{ ~Yr.0i.W  
sFilePath = value; (> 8fcQUBb  
} N@A#e/8  
F8=6!Qj  
G4RsH/  
public String getSFileName() Ko%rB+d  
{ qlgh$9  
return sFileName; Uc6U!X  
} R/b=!<  
2#E;5UYu  
*=sU+x&X  
public void setSFileName(String value) 1i>)@{P&BN  
{ UWusSi3+LG  
sFileName = value; gq0gr?  
} ~(&xBtg:}  
jWoo{+=D  
P{qn@:  
public int getNSplitter() Zv-6H*zM6  
{ k,@1rOf  
return nSplitter; Cu?$!|V  
} tP:xx2N_  
DX!$k[  
6g.@I!j E  
public void setNSplitter(int nCount) ?.Kl/8ml  
{ >eEf|tKO  
nSplitter = nCount; FCP5EN  
} A{c6XQR~z  
} |BW956fBU  
}YSH8d  
Qy$QOtrv  
/* -[7.VP   
**Utility.java p5 [uVRZ  
*/ -!}1{   
package NetFox; 1u` Z?S(  
% idnm  
@ =,J6  
public class Utility { $"UAJ-  
T }8aj  
.K93VTzy  
public Utility() 0SDCo\  
{ 9rid98~d  
q OXL(  
m0#hG x  
} w%ip"GT,  
7dakj>JM  
//线程睡眠 C9nNziws  
public static void sleep(int nSecond) z^b\hR   
{ x``!t>)O  
try{ 1";~"p2(  
Thread.sleep(nSecond); O^<6`ku  
} P9'5=e@jB  
catch(Exception e) <T}#>xHs3  
{ O:U@m@7  
e.printStackTrace (); \vT8 )\  
} m&%N4Q~X>  
} m:^@AR1%d  
H}$#aXEAn  
//日志 T8\,2UWsj2  
public static void log(String sMsg) %sq=lW5R{b  
{ _ <~05Eh  
System.err.println(sMsg); '0=U+Egp  
} 4 '+)9&g  
~W#f,mf  
J)-owu;  
public static void log(int sMsg) 7]^Cg;EtM:  
{ *\`C! r  
System.err.println(sMsg); jsG9{/Ov3  
} %z2nas$$g  
} p!691LI  
O3_Mrn(R  
! of7]s  
/* jab]!eY  
**TestMethod.java X-duG*~  
*/ H{V-C_  
package NetFox; e,x@?L*  
o O|^ [b#  
Q,4F=b  
public class TestMethod { QZfPd\Q5  
mA."*)8VNg  
@Yg7F>s  
public TestMethod() ::R^ w"  
{ ///xx/weblogic60b2_win.exe a} /Vu"  
try{ jn7} jWA  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $ -y+97  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Uyh   
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^U =`Rx  
fileFetch.start(); ! Q#b4f  
} l:ED_env:  
catch(Exception e){e.printStackTrace ();} _5)#{ o<  
AVJk  
GGBe/X  
} a~%ej.)l  
d!d 3r W;A  
^Y&Cm.w  
public static void main(String[] args) ^d"J2n,7L  
{ .$yw;go3  
new TestMethod(); Q\oUZnD$=  
} }}2 kA  
} 5A)w.i&V  
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