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http断点续传简单实现(java)

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/* lLLPvW[Q  
**SiteFileFetch.java `@{(ijg.  
*/ pRA%07?W  
package NetFox; s01=C3  
import java.io.*; V,]Fh5f  
import java.net.*; ?Cv([ ^Y.u  
FIx|4[&>S  
0rxGb} b*  
public class SiteFileFetch extends Thread { WAJ KP"  
Q;GcV&f;f  
#X2wy$GTG  
SiteInfoBean siteInfoBean = null; //文件信息Bean IUz`\BO4  
long[] nStartPos; //开始位置 S2>$S^[U  
long[] nEndPos; //结束位置 m;!X{CV  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 JA4}B wn  
long nFileLength; //文件长度 (6&"(}Pai  
boolean bFirst = true; //是否第一次取文件 hx ^l  
boolean bStop = false; //停止标志 gy xC)br  
File tmpFile; //文件下载的临时信息 *'@ sm*  
DataOutputStream output; //输出到文件的输出流 QwL*A `@  
yatZ Al(B  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) M5 ^qc  
public SiteFileFetch(SiteInfoBean bean) throws IOException }:(;mW8 D  
{ z>)lp$  
siteInfoBean = bean; `nY.&YT  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); >X*Y jv:r  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); NdrR+t^#  
if(tmpFile.exists ()) yQf(/Uxk*x  
{ Adgfo)X5  
bFirst = false; 2Sk"S/4}Z  
read_nPos(); k106fT]eX  
} ]~ !CJ8d  
else 5F#FC89Kk  
{ yT[=!M  
nStartPos = new long[bean.getNSplitter()]; -Ua&/Yd/}  
nEndPos = new long[bean.getNSplitter()]; Z/d {v:)  
} ^ 4*#QtO  
JF=T_SH^U  
z<gII~%  
TeFi[1  
} \"w+4}  
wj5,_d)  
PbFbi hg  
public void run() Q 7\j:.  
{ T8d=@8g,%  
//获得文件长度 t#w,G  
//分割文件 g!OcWy)7  
//实例FileSplitterFetch [3x},KM  
//启动FileSplitterFetch线程 ).-#  
//等待子线程返回 p{+F{e  
try{ <'\!  
if(bFirst) .o]9 HbIk5  
{ 204"\ mv  
nFileLength = getFileSize(); #qv!1$}2  
if(nFileLength == -1) u=Xpu,q  
{ P"o|kRO  
System.err.println("File Length is not known!"); Z[>fFg~N4  
} 8U}+9  
else if(nFileLength == -2) I'[;E.KU  
{ Rtlc&Q.b  
System.err.println("File is not access!"); umCmxm r&  
} D !{e  
else \fp'=&tp~a  
{  cp0yr:~  
for(int i=0;i<nStartPos.length;i++) A4Q{(z-?  
{ 5rmQ:8_5  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); KtArV  
} HZ1nuA  
for(int i=0;i<nEndPos.length-1;i++) MhJA8| B6|  
{ =woP~+  
nEndPos = nStartPos[i+1]; dI>cPqQ  
} :jC$$oC].  
nEndPos[nEndPos.length-1] = nFileLength; A[F_x*S  
} mF UsTb]f  
} GMB3`&qh  
e wWw  
<[u(il  
//启动子线程 GVfRy@7n  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ddd2w  
for(int i=0;i<nStartPos.length;i++) 1(RRjT 9  
{ 1.TIUH1  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &Pc.[k  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /1$u|Gs *  
nStartPos,nEndPos,i); Yq4nmr4  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cI/}r Z+  
fileSplitterFetch.start(); b"nkF\P@Fj  
} f1sp6S0V\  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $4qM\3x0,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); reM~q-M~o@  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OR37  
nEndPos = " + nFileLength); J :O&2g"g  
// fileSplitterFetch[nPos.length-1].start(); s_^N=3Si   
%@|)&][hO  
kUfbB#.5L  
//等待子线程结束 %~kE,^  
//int count = 0; YY(_g|;?8  
//是否结束while循环 {u -J?(s}  
boolean breakWhile = false; 6']G HDK  
#{#k;va  
Ro4!y:2|  
while(!bStop) e/#6qCE  
{ A/"2a55  
write_nPos(); h:sf?X[  
Utility.sleep(500); '-Oh$hqCx|  
breakWhile = true; U#Iwe=  
ov daK"q2  
dBS_N/  
for(int i=0;i<nStartPos.length;i++) ~*]7f%L-  
{ G9GHBwT  
if(!fileSplitterFetch.bDownOver) YB!f=_8  
{ W\ mgM2p  
breakWhile = false; 0)7v _|z  
break; 4mtO"'|  
} ?$uEN_1O\@  
} D,|TQ Q  
if(breakWhile) uH,/S4?X  
break; R(,m!  
B-$zioZ  
wXZ9@(^  
//count++; &9z&#`AY]>  
//if(count>4) eu~ u-}.  
// siteStop(); ~%eE%5!k  
} ZS=;)  
q&_\A0  
!ZvVj\{  
System.err.println("文件下载结束!"); Bjj =UtI  
} ~)[ pL(4  
catch(Exception e){e.printStackTrace ();} IXlk1tHN4I  
} 4\k{E-x $  
uI& 0/  
l!W!Gz0to  
//获得文件长度 9a_UxF+6/  
public long getFileSize() _a|g >  
{ /q,=!&f2  
int nFileLength = -1; H8B2{]HAt  
try{ B&y?Dc  
URL url = new URL(siteInfoBean.getSSiteURL()); r!w*y3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); % tC[q   
httpConnection.setRequestProperty("User-Agent","NetFox"); Iza;~8dH5  
SGba6b31  
5|>ms)[RQ  
int responseCode=httpConnection.getResponseCode(); i )$+#N  
if(responseCode>=400) eibkG  
{ ~D`R"vzw=  
processErrorCode(responseCode); uFhPNR2l  
return -2; //-2 represent access is error bj0<A  
} Ciz,1IV  
5w{U/v$Z  
(FZ8T39  
String sHeader; ?<Hgq8J  
b$_qG6)IJO  
p@O,-&/D  
for(int i=1;;i++) 6ecx!uc$  
{ )8'v@8;-  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7GG`9!l]D  
//Utility.log(in.readLine()); UH;bg}=8  
sHeader=httpConnection.getHeaderFieldKey(i); a`]ZyG*P  
if(sHeader!=null) {7MY*&P$,  
{ v6 |[p  
if(sHeader.equals("Content-Length")) /~7M @`1  
{ mG@[~w+  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RlU?F  
break; R>1oF]w  
} `ZO5-E  
} i,% N#  
else Pgq(yPC  
break; vpOGyvI  
} c&aqN\'4"  
} 4:733Q3oK  
catch(IOException e){e.printStackTrace ();} m=/HUt3(&0  
catch(Exception e){e.printStackTrace ();} mA_EvzXk\  
;-l^X%r  
|nr;OM  
Utility.log(nFileLength); }H saJ=1U  
fA0wQz]u  
4 >H0a  
return nFileLength; "*V'   
} =CS$c?  
[u J<]  
[D(JEO@ :  
//保存下载信息(文件指针位置) )56L`5#tS  
private void write_nPos() gp~-n7'~O  
{ _ouZd.  
try{  | z_av  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ol<LL#<j4  
output.writeInt(nStartPos.length); =knLkbiq7,  
for(int i=0;i<nStartPos.length;i++) YcR: _ac  
{ nw_|W)JVQ  
// output.writeLong(nPos); $Fy~xMA8O  
output.writeLong(fileSplitterFetch.nStartPos); 2`ERrh^i"  
output.writeLong(fileSplitterFetch.nEndPos); Z![#Uz.z  
} aHI~@  
output.close(); 3[l\l5'm8  
} p]Qe5@NT  
catch(IOException e){e.printStackTrace ();} CDW| cr{  
catch(Exception e){e.printStackTrace ();} 7~ZG"^k  
} SrOv* D3  
fIatp  
:B|rs&  
//读取保存的下载信息(文件指针位置) cXN0D\%`  
private void read_nPos() #BS!J&a  
{ QfM^J5j.M?  
try{ R`@7f$;wG  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); a8%T*mk(  
int nCount = input.readInt(); +|K,\ {'U  
nStartPos = new long[nCount]; ~ 7Nqwwx  
nEndPos = new long[nCount]; */TO $ ^s  
for(int i=0;i<nStartPos.length;i++) Ae2Y\sAV  
{ @E h(GZN  
nStartPos = input.readLong(); XRyeEwA;pp  
nEndPos = input.readLong(); m9jjKu]|  
} ;i+(Q%LO  
input.close(); `Pwf?_2n-  
} W=|'&UU Ul  
catch(IOException e){e.printStackTrace ();} XuZgyt"=r  
catch(Exception e){e.printStackTrace ();} >s,*=a  
} V/R@ =[  
L;b-=mF  
(5[#?_~  
private void processErrorCode(int nErrorCode) I/v#!`L  
{ -(}N-yu  
System.err.println("Error Code : " + nErrorCode); NA/Sv"7om  
} 3=UufI  
iU~d2R+  
4K4u]"1  
//停止文件下载 ~EYdEqS)  
public void siteStop() 9jl\H6JY|  
{ |c-`XC2g  
bStop = true; C)9-{Yp  
for(int i=0;i<nStartPos.length;i++) a"1LF`  
fileSplitterFetch.splitterStop(); miCY?=N`  
7Bf4ojKt  
o(t`XE['<  
} &qa16bz  
} ZC^?ng  
//负责部分文件的抓取 *S4&V<W>  
**FileSplitterFetch.java 6+PP(>em  
*/ dPgA~~  
package NetFox; -ucR@P]  
}:0HM8B7!  
mcQ\"9;pY  
import java.io.*; 6jl{^dI  
import java.net.*; (ueH@A"9;  
}JT&lyO< b  
D6e<1W  
public class FileSplitterFetch extends Thread { *1>Tc,mb  
_F8-4  
U[#q"'P|l  
String sURL; //File URL $.B}zY{  
long nStartPos; //File Snippet Start Position ~ r$I&8  
long nEndPos; //File Snippet End Position Ox'K C  
int nThreadID; //Thread's ID % %2~%FVb  
boolean bDownOver = false; //Downing is over !yV)EJ:$  
boolean bStop = false; //Stop identical 15DlD`QV  
FileAccessI fileAccessI = null; //File Access interface {>brue*)  
y>RqA *J  
j{zVVT  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ' 94HVag  
{ W}wd?WIps  
this.sURL = sURL; icK U)  
this.nStartPos = nStart; ?C6`  
this.nEndPos = nEnd; \OK}DhY#  
nThreadID = id; PKs$Q=Ol<|  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ({!*&DVu  
} |txzIc.#  
'_g*I  
Yt4v}{+  
public void run() ,l\D@<F  
{ M49Hm[0(  
while(nStartPos < nEndPos && !bStop) VC!g,LU|-  
{ b1ZHfe:  
qEjsAL  
CR|>?9V  
try{ `R$bx 64  
URL url = new URL(sURL); {Z[kvXf"mZ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ):Ekf2  
httpConnection.setRequestProperty("User-Agent","NetFox"); s: MJ{r(s  
String sProperty = "bytes="+nStartPos+"-"; $5>x)jr:w+  
httpConnection.setRequestProperty("RANGE",sProperty); ,z0E2  
Utility.log(sProperty); :!,.c $M  
81wmKqDEs  
'FN3r  
InputStream input = httpConnection.getInputStream(); ^}GR!990  
//logResponseHead(httpConnection); H329P*P  
yhyh\.  
[3W+h1  
byte[] b = new byte[1024]; uRw%`J4H  
int nRead; Fd9Z7C  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "QY~V{u5  
{ jH4Wu`r;m  
nStartPos += fileAccessI.write(b,0,nRead); 9p"';*{=  
//if(nThreadID == 1) wtGb 3D"am  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0j{KZy  
} a3(f\MM xE  
y? 65*lUl  
/p@0Q [E  
Utility.log("Thread " + nThreadID + " is over!"); MK4CggoC  
bDownOver = true; '}NH$ KA  
//nPos = fileAccessI.write (b,0,nRead); c-a;nAR  
} f<3r;F7  
catch(Exception e){e.printStackTrace ();} 0 f"M-x  
} >[g'i+{  
} 7jF2m'(  
t]pJt  
&44?k:  
//打印回应的头信息 ]^l-k@  
public void logResponseHead(HttpURLConnection con) Xc]Q_70O  
{ \Ng[lN  
for(int i=1;;i++) H0mDs7  
{ O,KlZf_B  
String header=con.getHeaderFieldKey(i); =TXc - J  
if(header!=null) k8"[)lDc.  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kc:2ID&  
Utility.log(header+" : "+con.getHeaderField(header)); &oiBMk`*  
else z[_Gg8e  
break; YA^g[,  
} ,[Z;"wE  
} `#N7ym;s@  
a^&3?3   
ia /_61%  
public void splitterStop() {{_,YO^w  
{ !GVxQll[f  
bStop = true; ' 9  
} & |o V\L  
-3:x(^|:K  
YcBAW4B`  
} fBt7#Tc=U  
k$ } 6Qd  
T k4"qGC.  
/* ~# |p=Y  
**FileAccess.java rhvsd2 zi  
*//文件访问(定位,写) 6T~xjAuJ3T  
package NetFox; SYTzJK@vZJ  
import java.io.*; rW3fd.;kss  
cj/FqU"  
gG=E2+=uy  
public class FileAccessI implements Serializable{ bDPT1A`F  
gs77")K&  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /-ky'S9  
RandomAccessFile oSavedFile;  Z@`HFZJ  
long nPos; O8ZHIs  
PK* $  
b%,`;hy{  
public FileAccessI() throws IOException -f:uNF]Ls  
{ YEqWTB|w  
this("",0); Bhrp"l +|  
} :!Tb/1  
v4Q8RE?  
{z}OZHJN  
public FileAccessI(String sName,long nPos) throws IOException ) 4'@=q  
{ /1lUFL2D  
oSavedFile = new RandomAccessFile(sName,"rw"); g@lAk%V4  
this.nPos = nPos; =>6'{32W_  
oSavedFile.seek(nPos); 89)rss  
} Y,@{1X`0@3  
+P<LoI  
+<H)DPG<  
public synchronized int write(byte[] b,int nStart,int nLen) -.E<~(fad  
{ P1ab2D  
int n = -1; ]Z\.Vx  
try{ R#Bdfmld q  
oSavedFile.write(b,nStart,nLen); ;=6~,k)  
n = nLen; 3J}bI {3  
} #`4ma:Pj  
catch(IOException e) jM3{A;U2  
{ <&rvv4*H  
e.printStackTrace (); YvK8;<k@-?  
} ?79ABm a  
FiqcM-Af4  
R{hKl#j;>  
return n; f+huhJS5e  
} gI^*O@Q4{b  
.gWYKZM  
UpS`KgF"v  
} PGHl:4`Es!  
6l>$N?a  
xGeRoW(X  
/* Y75,{1\l0  
**SiteInfoBean.java RW|3d<Fj  
*/ X@)5F 9  
package NetFox; {e?D6`#x  
mPxph>o  
9_F2nmEv  
public class SiteInfoBean { :_Y@,CpIEg  
GKwm %A  
PDo%ob\Ym  
private String sSiteURL; //Site's URL eVDI7W:(Sn  
private String sFilePath; //Saved File's Path *eytr#0B-  
private String sFileName; //Saved File's Name iVt6rX  
private int nSplitter; //Count of Splited Downloading File x,z+l-y  
NQ!jkojD  
q8.K-"f(Q  
public SiteInfoBean() MD S;qZx=  
{//nSplitter的缺省值为5 *#,wV  
//default value of nSplitter is 5 Jx@3zl  
this("","","",5); .4~n|d>z  
} \0m[Ch}~ey  
70L{u+wIy  
=x~HcsJ8!R  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +)FB[/pXk  
{ W9?Vh{w  
sSiteURL= sURL; T'l >$6  
sFilePath = sPath; {ls$#a+d  
sFileName = sName; ^~2GhveBV  
this.nSplitter = nSpiltter; 0t1WvW  
)sVz;rF<  
5/Q^p"  
} <ok/2v  
,&!Txyye  
0Q=4{*:?  
public String getSSiteURL() A5zT^!`[  
{ 'tp1|n/1  
return sSiteURL; vO"Sy{)Z>  
} Z| Z447_  
!t6:uC7H  
ayuj)]b  
public void setSSiteURL(String value) A_}F  
{ s3W)hU)  
sSiteURL = value; x(7K=K']  
} m6)8L?B   
9Bl_t}0  
k#% BxT  
public String getSFilePath() mh!;W=|/"  
{ <IGQBu#ZH  
return sFilePath; 7%9Sz5z  
} {SW}S_  
Ym5q#f)|  
3ADT Yt".  
public void setSFilePath(String value) ` IiAtS  
{ _YY:}'+  
sFilePath = value; *?K3jy{  
} hp!UW  
`ej  
# &o3[.)9  
public String getSFileName() Q uy5H  
{ Kgi%Nd  
return sFileName; RiF~-;v&  
} qIa|sV\w0  
AxUj CerNf  
=u(. Y  
public void setSFileName(String value) EaG3:<>J  
{ n0kBLn  
sFileName = value; q3B#rje>h  
} _H|x6X1-  
|<P]yn  
`AeId/A4n  
public int getNSplitter() `(<XdlOj  
{ u<./ddC  
return nSplitter; 9. Q;J#;1  
} (t1:2WY@  
1"009/|   
|r!G(an1x4  
public void setNSplitter(int nCount) *?7Ie;)  
{ DF/p{s1Y3  
nSplitter = nCount; l. ?R7f  
} MVK='  
} el39HB$  
dy;Ue5  
C".&m  
/* ]L%qfy4  
**Utility.java  z@^l1)m  
*/ aHe/MucK  
package NetFox; lqa.Nj  
a-,!K  
0n|op:]BHM  
public class Utility { bN@V=C3  
ZkkXITQkPM  
@kn0f`  
public Utility() ^)conSm  
{ 5V4Ze;K  
z,[4 BM  
|AW[4Yn>  
} P*XLm  
K_',Gd4L  
//线程睡眠 s={AdQ  
public static void sleep(int nSecond) hgX@?WWR  
{ 1 e1$x@\\  
try{ IL?3>$,  
Thread.sleep(nSecond); v{^_3 ]  
} wP- pFc  
catch(Exception e) f@T/^|`mh  
{ ~cVFCM  
e.printStackTrace (); deHhl(U;  
} DTk)Y-eQ  
} \T'uFy9&a  
11}X2j~Ww  
//日志 h}i /u  
public static void log(String sMsg) Pfu2=2Ra  
{ }x`W+r  
System.err.println(sMsg); K?,eIZ{.S  
} g8 ,V( ^  
RyKsM.   
V03U"eI="  
public static void log(int sMsg) ttuQ ,SD  
{ *g]q~\b/;  
System.err.println(sMsg); b"t95qlL  
} iXK.QktHw  
} ilEWxr;,  
3:7J@>  
-z./6dQ  
/* DcE)6z#  
**TestMethod.java e)LRD&Q  
*/ uA7~`78  
package NetFox; %+YLe-\?  
\R yOexNZ  
FA<|V!a  
public class TestMethod { R<@s]xX_  
M5s>;q)  
j|TcmZGO  
public TestMethod() I4:4)V?  
{ ///xx/weblogic60b2_win.exe {v+,U}  
try{ \:-#,( .V  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S(eCG2gR  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P7O$*  
SiteFileFetch fileFetch = new SiteFileFetch(bean); )1wC].RFYm  
fileFetch.start(); 4eK!1|1  
} F0W4B  
catch(Exception e){e.printStackTrace ();} S:4'k^E  
,3 &XV%1  
lfp[(Ph)9  
} &[$qA  
eRc+.m[  
Qyvn A|&  
public static void main(String[] args) C']TO/2q  
{ z^$DXl@)h  
new TestMethod(); Yb\t0:_  
} nfET;:{  
} KWbnSL8  
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