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http断点续传简单实现(java)

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/* s<GR ?  
**SiteFileFetch.java jDyG~de  
*/ UWf@(8  
package NetFox; NFAjh?#  
import java.io.*; $,s"c(pv[,  
import java.net.*; [v,Y-}wQ)  
t'7A-K=k3  
l-~ o&n  
public class SiteFileFetch extends Thread { #9's^}i  
w1N-`S:  
(8XP7c]5  
SiteInfoBean siteInfoBean = null; //文件信息Bean rQrh(~\:  
long[] nStartPos; //开始位置 @v:p)|Ne;  
long[] nEndPos; //结束位置 (E*pM$  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 /x2MW5H  
long nFileLength; //文件长度 8c1ma  
boolean bFirst = true; //是否第一次取文件 Ig.9:v`  
boolean bStop = false; //停止标志 UA%tI2  
File tmpFile; //文件下载的临时信息 [f8mh88 r  
DataOutputStream output; //输出到文件的输出流 )C1ihm!7\  
UHaY|I${U  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 20NotCM  
public SiteFileFetch(SiteInfoBean bean) throws IOException +~ZFao qf  
{ oiKY2.yW  
siteInfoBean = bean; IXz)xdP  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); y%wjQC 0~  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); &_Vd  
if(tmpFile.exists ()) r;~2NxMF/  
{ pOmHxFOOK  
bFirst = false; 'Cq)/}0  
read_nPos(); C7hJE -  
} 01br l^5K  
else B]_NI=d  
{ r ?e''r  
nStartPos = new long[bean.getNSplitter()]; !#b8QER  
nEndPos = new long[bean.getNSplitter()]; 9_/dj"5  
} xO` `X<  
K'DRX85F  
F?3zw4Vt~  
FL8?<bU  
} ]K^#'[  
?T (@<T  
8s@k0T<O  
public void run() C"JFN(f  
{ C5ia9LpRX  
//获得文件长度 :Qekv(z  
//分割文件 9Q.}jV  
//实例FileSplitterFetch ww^!|VVa  
//启动FileSplitterFetch线程 &>KZ4%&?  
//等待子线程返回 aR@s. ll  
try{ o;^k"bo6   
if(bFirst) $!m (S&f  
{ wpW3%r;9  
nFileLength = getFileSize(); 9Z_!}eY2mc  
if(nFileLength == -1) wV& UB@  
{ dJYW8pcKT  
System.err.println("File Length is not known!"); {] Zet}2  
} % a9C]?  
else if(nFileLength == -2) Mu>WS)1lS  
{ 2 yY.rs  
System.err.println("File is not access!"); E$?:^ausu  
} N Dg*8i  
else \l d{Z;e  
{ C3#mmiL-  
for(int i=0;i<nStartPos.length;i++) qe@ctHpn  
{ hp< NVST  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); K[G=J  
} rO;Vr},3\%  
for(int i=0;i<nEndPos.length-1;i++) .~L^h/)Gjy  
{ 'UN 'gXny  
nEndPos = nStartPos[i+1]; c1CUG1i  
} +o*&JoC  
nEndPos[nEndPos.length-1] = nFileLength; [$+N"4  
} :"utFBO  
} YS|Ve*t(L=  
-$0w-M8'  
ta)'z@V@g  
//启动子线程 !}$,) ~<+H  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; oDvE0"Sz  
for(int i=0;i<nStartPos.length;i++) PRpW*#"EI  
{ So^;5tG  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :~gG]|F  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E5EAk6  
nStartPos,nEndPos,i); q n2X._`  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8`? vWJS  
fileSplitterFetch.start(); `~S ; UG   
} Dg_AoC  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %Q2<bj]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iAWd 9x  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", __Tg1A  
nEndPos = " + nFileLength); PL6f**{-  
// fileSplitterFetch[nPos.length-1].start(); ~ v21b?   
=Kh1 HU.F  
y"o@?bny  
//等待子线程结束 FJYc*l  
//int count = 0; *|F ;An.N^  
//是否结束while循环 ~Y3"vdd  
boolean breakWhile = false; "7RnT3  
.V.x0  
8G6[\P3fQ  
while(!bStop) 2TxHY|4  
{ }-8ZSWog6f  
write_nPos(); WXgGB[x  
Utility.sleep(500); {YoK63b$  
breakWhile = true; q=+AN</  
M6mJ'Q482  
ZY Ci&l  
for(int i=0;i<nStartPos.length;i++) W.O]f.h  
{ fkjo  
if(!fileSplitterFetch.bDownOver) *>%tx k:)  
{ O,+ZD^  
breakWhile = false; ?~_[/  
break; }wkZ\q[  
} @$bEY#*C  
} ,^#{k!uaC{  
if(breakWhile) 74u_YA<"  
break; )kl(}.9X  
sBuOKT/j  
&qO#EEqG]  
//count++; *53@%9 {u  
//if(count>4) /ivA[LSS  
// siteStop(); "N\tR[P!  
} o(5eb;"yi>  
y))) {X  
BWHH:cX  
System.err.println("文件下载结束!"); TTSyDl  
} 1[&V6=n  
catch(Exception e){e.printStackTrace ();} }kK6"]Tj  
}  `[=3_  
]3/_?n-"`  
zP(UaSXz/  
//获得文件长度 d2!A32m  
public long getFileSize() hfBZ:es+  
{ XX:?7:j}[8  
int nFileLength = -1; f'>270pH  
try{ [Jjb<6[o  
URL url = new URL(siteInfoBean.getSSiteURL()); ~s[St0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /l)|B  
httpConnection.setRequestProperty("User-Agent","NetFox"); pm 4"Q!K  
c%bGVRhE  
;vDjd2@  
int responseCode=httpConnection.getResponseCode(); i4XE26B;e  
if(responseCode>=400) 4EZl (v"f`  
{ )8rN   
processErrorCode(responseCode); A/%+AH(  
return -2; //-2 represent access is error )PNeJf|@  
} q#n0!5Lv2  
0M=U >g)  
M'"@l $[QM  
String sHeader; fZH";_"1  
k-`5T mW  
ZI0C%c.~  
for(int i=1;;i++) t;?TXAA  
{ f L}3I(VK  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IB sQaxt.  
//Utility.log(in.readLine()); <:t D m  
sHeader=httpConnection.getHeaderFieldKey(i); e/{1u$  
if(sHeader!=null) ^q$m>|KI  
{ hA0g'X2eC  
if(sHeader.equals("Content-Length")) ha%3%O8Z  
{ mK>c+ u)  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _?+gfi+  
break; 4 )U,A~ !  
} 0bt"U=x4  
} T/$6ov+K  
else k^vsQ'TD  
break; h ?Ni5  
} IQ`#M~:  
} "0&+ `7  
catch(IOException e){e.printStackTrace ();} X9YYUnR2  
catch(Exception e){e.printStackTrace ();} r@XH=[:  
_eE hIQ9  
z'(][SB  
Utility.log(nFileLength); J!5>8I(_wX  
)0Lno|l  
^Iz(V2  
return nFileLength; x2KIGG ^  
} ;Rz+4<  
b\dzB\,&  
etPb^&#$  
//保存下载信息(文件指针位置) }!W,/=z*  
private void write_nPos() F_?aoP&5  
{ @ z{E  
try{ 20O\@}2q2M  
output = new DataOutputStream(new FileOutputStream(tmpFile)); n'&Cr0{  
output.writeInt(nStartPos.length); ~`<(T)rs  
for(int i=0;i<nStartPos.length;i++) 6;:s N8M+1  
{ C_RxJWka  
// output.writeLong(nPos); **%/Ke[  
output.writeLong(fileSplitterFetch.nStartPos); k6p Xc<]8  
output.writeLong(fileSplitterFetch.nEndPos); 5c W2  
} "i}?jf {a  
output.close(); !5/jDvh  
} Q|O! cEW/  
catch(IOException e){e.printStackTrace ();} |Zn |?#F  
catch(Exception e){e.printStackTrace ();} 9qHbV 9,M  
} [KT'aGK$  
"8'aZ.P  
%s^2m"ca}=  
//读取保存的下载信息(文件指针位置) ]4$t'wI.  
private void read_nPos() !@r1B`]j+"  
{ ?0{8fGM4  
try{ NJVAvq2E.  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RwG@C|sG  
int nCount = input.readInt(); h{R>L s  
nStartPos = new long[nCount]; #K5)Rb-H  
nEndPos = new long[nCount]; }=+J&cR  
for(int i=0;i<nStartPos.length;i++) P{'T9U|O-  
{ (}E ] g  
nStartPos = input.readLong(); 0&YW#L|J  
nEndPos = input.readLong(); ^Ia:e ?)W  
} 3Pj 6(cf  
input.close(); A`NkgVq5:  
}  u Z(vf  
catch(IOException e){e.printStackTrace ();} rfl-(_3  
catch(Exception e){e.printStackTrace ();} s Y^#I  
} f:=y)+@1My  
OF4iGFw  
;{zgp  
private void processErrorCode(int nErrorCode) O e-FI+7  
{ Nan@SuKY  
System.err.println("Error Code : " + nErrorCode); %`kO\q_  
} E*uz|w3S)Y  
x}8 U\  
Jvk!a~e  
//停止文件下载 DvBL #iC   
public void siteStop() dK5|tWJX  
{ Q :<&<i=I  
bStop = true; ^UB<U#8,  
for(int i=0;i<nStartPos.length;i++) vp"b_x1-  
fileSplitterFetch.splitterStop(); AB!P(  
epcBr_}  
wVSk.OOB  
} DRo?7 _  
} "M)kV5v%  
//负责部分文件的抓取 y@5{.jsr_  
**FileSplitterFetch.java .d^XM  
*/ 6@"lIKeP  
package NetFox; GE2^v_  
]dx6E6A,  
yJ\K\\]  
import java.io.*; *?'^R c  
import java.net.*; yX%Xjo__*t  
!`3q9RT3."  
l"I G;qO.  
public class FileSplitterFetch extends Thread { yXuF<+CJ  
MDHTZ9 4\Q  
|KV|x ^fJ  
String sURL; //File URL /M}jF*5N  
long nStartPos; //File Snippet Start Position 69z,_p$@:  
long nEndPos; //File Snippet End Position zdL"PF  
int nThreadID; //Thread's ID #6'x-Z_  
boolean bDownOver = false; //Downing is over Nq$Xe~,*  
boolean bStop = false; //Stop identical q_h=O1W  
FileAccessI fileAccessI = null; //File Access interface +A 4};]W|  
@w%{yzr%  
6AM-^S@  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =B0#z]qu  
{ -HE@wda  
this.sURL = sURL; ^ #6Ei9di  
this.nStartPos = nStart; -^Pn4y]A)  
this.nEndPos = nEnd; k>2tC<  
nThreadID = id; =JqKdLH  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tX<. Ud  
} 2MV!@rx  
XLog+F$`  
%^5|3l3y  
public void run() sPu@t&$  
{ TA2?Ia;@xV  
while(nStartPos < nEndPos && !bStop) t_VF=B^LuR  
{ _(qU%B  
!| G 8b'  
&jg..R  
try{ =i`#0i2(  
URL url = new URL(sURL); 'b?Px}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (M>[D!Yt  
httpConnection.setRequestProperty("User-Agent","NetFox"); i`FskEoijq  
String sProperty = "bytes="+nStartPos+"-"; 4Ou|4WjnL  
httpConnection.setRequestProperty("RANGE",sProperty); 0R#T3K}  
Utility.log(sProperty); I;Sg 9`k=  
cZ<@1I5QK  
D2060ze  
InputStream input = httpConnection.getInputStream(); F2B9Q_>P  
//logResponseHead(httpConnection); g RX`61  
1x"S^j   
I6q]bQ="  
byte[] b = new byte[1024]; (jV_L 1D  
int nRead; "@!B"'xg  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o 0-3[W'x<  
{ Cwb }$=p'  
nStartPos += fileAccessI.write(b,0,nRead); )kBN]>&R  
//if(nThreadID == 1) {JJq/[j  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -Um|:[*I  
} \Q CH.~]  
<b5J"i&m  
4v=NmO }  
Utility.log("Thread " + nThreadID + " is over!"); \Y>!vh X  
bDownOver = true; -W#-m'Lvu  
//nPos = fileAccessI.write (b,0,nRead); 'Q^P#<<  
} l2AAEB_C.  
catch(Exception e){e.printStackTrace ();} e=8z,.Xk  
} &fyT}M A  
} K}r@O"6*\  
|i}5vT78  
_ ?\4k{ET  
//打印回应的头信息 O%>FKU>(?  
public void logResponseHead(HttpURLConnection con) rA">< pH  
{ P B W.nm  
for(int i=1;;i++) B9Ha6kj  
{ }'"4q  
String header=con.getHeaderFieldKey(i); #dd-rooQuD  
if(header!=null) Ykt{]#  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5S;|U&f|  
Utility.log(header+" : "+con.getHeaderField(header)); H.n+CR  
else cAL*Md8+  
break; "TLY:V  
} n#NE.ap$&,  
} SWrt4G  
,X&(BQj h  
.y)Y20=o!  
public void splitterStop() snl$v  
{ voD0 u  
bStop = true; >h[ {_+  
} MPn 6sf9M  
$69ef[b  
|?kZfr&9q  
} miq"3  
W@T_-pTCjK  
ThvVLK  
/* e%B;8)7  
**FileAccess.java ~&UfnO  
*//文件访问(定位,写) ZjOUk;H?  
package NetFox; `;:zZ8*  
import java.io.*; B?-~f^*,jG  
a2z1/Nh  
-kv'C6gB  
public class FileAccessI implements Serializable{ Me.t_)  
+FYQ7UE  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bsn.HT"5  
RandomAccessFile oSavedFile; ,pg\5b  
long nPos; Uc?4!{$X  
JyfWy  
d{gj8  
public FileAccessI() throws IOException ~<)CI0=  
{ >_<J=8|E  
this("",0); iJr 1w&GL$  
} G OzV#  
NY& |:F  
=s\RK   
public FileAccessI(String sName,long nPos) throws IOException v4YY6? 4  
{ kJOSGrg  
oSavedFile = new RandomAccessFile(sName,"rw"); 5W(S~}  
this.nPos = nPos; ToNRY<!  
oSavedFile.seek(nPos); h|DKD.  
} RyJN=;5p  
PN +<C7/  
fV\ eksBF  
public synchronized int write(byte[] b,int nStart,int nLen) L, k\`9bQ  
{ gLH#UwfJ  
int n = -1; qXb{A*J  
try{ HoFFce7o  
oSavedFile.write(b,nStart,nLen); ]rhxB4*1  
n = nLen; og! d  
} B F,rZZL  
catch(IOException e) cl4Vi%   
{ VgoN=S  
e.printStackTrace (); TsX(=N_  
} o C5}[cYD`  
R>3a?.X  
"]"!"#aMv  
return n; !GNLq.rQ  
} "(U%Vg|)  
!aVwmd'9  
l5 FM>q  
} Je5UVf3>2&  
+yh-HYo`  
E@f2hW2  
/* ;M95A  
**SiteInfoBean.java CXzN4!  
*/ w'Cn3b)`  
package NetFox; 5T,In+~Kd  
P/'9k0zs)  
-d|VXD5N  
public class SiteInfoBean { "n4' \ig  
N~w4|q!]  
Fp`MX>F  
private String sSiteURL; //Site's URL bc".R]  
private String sFilePath; //Saved File's Path @`</Z)  
private String sFileName; //Saved File's Name U;QN+fF]u  
private int nSplitter; //Count of Splited Downloading File #kuk3}&  
<MPoDf?h  
)bM #s">Y  
public SiteInfoBean() @rTAbEk{U  
{//nSplitter的缺省值为5 @\!9dK-W  
//default value of nSplitter is 5 icX$<lD  
this("","","",5); 6L2Si4OGjG  
} Ww }qK|D  
\[-z4Fxg|'  
LEUD6 M+~t  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !*U#,qY  
{ >-~2:d\M3  
sSiteURL= sURL; 0B4&!J  
sFilePath = sPath; `$X|VAS2  
sFileName = sName; 8@S5P$b};  
this.nSplitter = nSpiltter; xSQ0]vE  
5&uS700  
C&\vVNV;9  
} D-/aS5wM  
OfR\8hAY  
e' `xU  
public String getSSiteURL() d^&F%)AT  
{ $S"QyAH~-a  
return sSiteURL; Vs)%*1><  
} f> u{e~Q,  
7Y8B \B)w  
+dkbt%7M  
public void setSSiteURL(String value) )BuS'oB  
{ $rZ:$d.C  
sSiteURL = value; 4zF|}aiQ  
} Wgh4DhAW  
#&@qmps(T  
:\0q\2e[<  
public String getSFilePath() Se o3a6o  
{ +3c!.] o;  
return sFilePath; x bG'![OX  
} wGqQR)a  
_t:l:x.;T  
&zCqF=/9U  
public void setSFilePath(String value) $Qm-p?f  
{ KAR XC,z  
sFilePath = value; ~dIb>[7wy  
} (okCZ-_Jn  
fs]9HK/@\  
,tEvz  
public String getSFileName() !n=@(bT*wT  
{ brQkVt_)EE  
return sFileName; cI)XXb4  
} >!j= {hK  
W~1/vJ.*l  
m_%1I J  
public void setSFileName(String value) $RQ7rL3g{  
{ 5(/ 5$u   
sFileName = value; @G vDl=.  
} G-U%  
|~! R5|Q  
CS 7"mE`{  
public int getNSplitter()  s*gyk  
{ {__Z\D2I  
return nSplitter; _v=@MOI/J  
} \WM*2&  
#5?Q{ORN o  
;Yrg4/Ipa  
public void setNSplitter(int nCount) Mk=;UBb$X  
{ TQ? D*&  
nSplitter = nCount; H=vrF-#  
} DPfP)J:~  
} nL}bCX{  
mT.p-C  
IJ^KYho  
/* }2Lh'0 xY  
**Utility.java )x.}B4z  
*/ _tR%7%3*  
package NetFox; U.oxLbJ`  
(~oUd 4  
]fXMp*LvY  
public class Utility { rK*s/mX <  
%Fc, $ =  
hFw\uETu  
public Utility() _nR8L`l*z  
{ TEZ^Ia  
khl(9R4a  
/Yk2 |L  
} Kp *nOZ  
L~1u?-zu  
//线程睡眠 >4a@rT/  
public static void sleep(int nSecond) .>0e?A4,5?  
{ "(}xIsy  
try{ N\<RQtDg  
Thread.sleep(nSecond); [y y D-  
} Vw*;xek?  
catch(Exception e) ce{GpmW  
{ 4BG6C'`%  
e.printStackTrace (); L<>;E  
} tb7Wr1$<  
} #Zpp*S55  
(Rvke!"B  
//日志 Wh%qvV6]  
public static void log(String sMsg) w,NK]<dU@  
{ bz_Zk  
System.err.println(sMsg); pb`F_->uq  
} ?;.j)  
V *=To  
X75>C<  
public static void log(int sMsg) uROt h_/  
{ - Z"w  
System.err.println(sMsg); oC>QJ(o,8  
} =:a H2T*  
} eL9 RrSXz  
Q3#- q> ;7  
@oC8:  
/* h0NM5   
**TestMethod.java o #{D;'  
*/ ;$@7iL  
package NetFox; u~yJFIo  
|KF X0*70  
'v4#mf  
public class TestMethod { OiX>^_iDt  
$}<+~JpGfP  
1oaiA/bq  
public TestMethod() 1TfK"\  
{ ///xx/weblogic60b2_win.exe hS&,Gm`^  
try{ L)VEA8}  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~$>l@> xX  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y3$i?}?A  
SiteFileFetch fileFetch = new SiteFileFetch(bean); :W,6zv(..u  
fileFetch.start(); M#on-[  
} qUSImgg  
catch(Exception e){e.printStackTrace ();} v$"#9oh  
V\@h<%{^%7  
4EzmH)4G  
} #M6@{R2_  
o)'T#uK  
EA%(+tJ^0  
public static void main(String[] args) E;~gQ6vAI  
{ Qvs}{h/  
new TestMethod(); ,+P!R0PNH  
} o=?sMq1<  
} OA2<jrGB!  
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