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http断点续传简单实现(java)

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/* IyMKV$"  
**SiteFileFetch.java o_?YYw-:  
*/ LcQ\d*  
package NetFox; B7cXbUAQs  
import java.io.*; %0L 9)-R  
import java.net.*; l/SbJrM*  
5K,Y6I&$SJ  
Uc.K6%iI  
public class SiteFileFetch extends Thread { f"z96{zo  
Q~nc:eWD  
8xLvpgcZ  
SiteInfoBean siteInfoBean = null; //文件信息Bean <J\z6+,4E  
long[] nStartPos; //开始位置 L.>`;`dmY  
long[] nEndPos; //结束位置 <~'\~Zd+  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 [^#6.xH  
long nFileLength; //文件长度 %;GDg3L[p  
boolean bFirst = true; //是否第一次取文件 23zB@aE_?1  
boolean bStop = false; //停止标志 m+zzhv1  
File tmpFile; //文件下载的临时信息 gE|_hfm(  
DataOutputStream output; //输出到文件的输出流 *U8Pjb1  
8@Pv nOL  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) q* +}wP  
public SiteFileFetch(SiteInfoBean bean) throws IOException VGkwrS;+I  
{ >a[)F  
siteInfoBean = bean; Ao(Xz$cQfW  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); G;MmD?VJ g  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); awGI|d  
if(tmpFile.exists ()) S-*4HV_l  
{ &0~E+ 9b  
bFirst = false; ml\A)8O]j/  
read_nPos(); K%O%#Kk  
} (]1n!  
else qy"#XbBeV  
{ fQM:NI? 9?  
nStartPos = new long[bean.getNSplitter()]; tRFj<yuaq  
nEndPos = new long[bean.getNSplitter()]; 6|L<? X  
} }[k~JXt  
NZ7g}+GTG  
Jc95Ki1X  
eNR>W>;'  
} %N04k8z  
Y:XE4v/)@L  
z1K@AaRx  
public void run() N[:;f^bH49  
{ NJRk##Z  
//获得文件长度 A}W) La\  
//分割文件 fYBmW')  
//实例FileSplitterFetch a"@k11  
//启动FileSplitterFetch线程 nkUSd}a`r  
//等待子线程返回 /_rEI,[k  
try{ 2r4owB?  
if(bFirst) 3 - Nwg9 U  
{ @9Rg g9r  
nFileLength = getFileSize(); |uf{:U)  
if(nFileLength == -1) qbrY5;U  
{ c6VfFt6p  
System.err.println("File Length is not known!"); ;/l$&:  
} GgwO>[T  
else if(nFileLength == -2) }coSMTMv6  
{ QQ;<L"VW  
System.err.println("File is not access!"); <pyLWmO  
} [$:M/5y9  
else dY[ XNP  
{ _$g6Mj]1z  
for(int i=0;i<nStartPos.length;i++) qz[qjGdHg  
{ HGM? ?=  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); q% *-4GP  
} .LMOmc=(  
for(int i=0;i<nEndPos.length-1;i++) IsP-[0it  
{ e1ts/@V  
nEndPos = nStartPos[i+1]; =A[:]),v  
} =Y!x  
nEndPos[nEndPos.length-1] = nFileLength; YD>5zV%!D  
} jT/}5\  
} +c'b=n9j  
g2)jd[GM  
gJ;jh7e@  
//启动子线程 k%2woHSu&  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^K[WFiN}  
for(int i=0;i<nStartPos.length;i++) !A_<(M<  
{ }#'I,?_k  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [&H$Su}$0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b~$B 0o)  
nStartPos,nEndPos,i); DNTkv_S  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3%HF"$Gg  
fileSplitterFetch.start(); 9rD6."G  
} PH!^ww6  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f[r?J/;P9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'OEh'\d+x  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `eZ +Pf".  
nEndPos = " + nFileLength); R;yi58Be  
// fileSplitterFetch[nPos.length-1].start(); lSW6\jX  
5l_ >QB  
V%|CCrR  
//等待子线程结束 *aem5 E`c  
//int count = 0; ?so=k&I-M  
//是否结束while循环 J]h$4"  
boolean breakWhile = false; c qWX*&2_  
6I8A[   
 <xn96|$  
while(!bStop) \}:RG^*m  
{ &Hl*Eg f  
write_nPos(); H]I^?+)9  
Utility.sleep(500); O4c[,Uq8~  
breakWhile = true; !\'NBq,  
h eR$j  
@Yzdq\FI  
for(int i=0;i<nStartPos.length;i++) _0GM!Cny  
{ mK Ta.  
if(!fileSplitterFetch.bDownOver) EdC^L`::  
{ [<0\v<{`L  
breakWhile = false; b '9L}q2m  
break; @gc|Z]CV  
} 'c[|\M!u  
} {.HFB:<!}  
if(breakWhile) v,eTDgw  
break; __mnz``/Y  
e6 &-f  
178u4$# b  
//count++; eV"Za.a.  
//if(count>4)  0m&  
// siteStop(); $ap6Vxjr  
} Bu{1^g:  
{J[5 {]Je[  
Y%GIKtP  
System.err.println("文件下载结束!"); ?7eD< |  
} <T^:`p/]4  
catch(Exception e){e.printStackTrace ();} ' K\ $B_  
} . a@>1XO  
<+r<3ZBA  
n[f<]4<  
//获得文件长度 12olVTuw  
public long getFileSize() kv8 /UW  
{ GEd JB=  
int nFileLength = -1; {=Y3[  
try{ jmkVolz  
URL url = new URL(siteInfoBean.getSSiteURL()); KD(}-zUs  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Cju%CE3a  
httpConnection.setRequestProperty("User-Agent","NetFox"); #q-7#pp  
USrBi[_ci\  
=X24C'!Mpe  
int responseCode=httpConnection.getResponseCode(); 13f@Ox$  
if(responseCode>=400) S!JwF&EW  
{ jb'A Os  
processErrorCode(responseCode); } N$soaUs  
return -2; //-2 represent access is error $Y3mO ~  
} %=G*{mK  
i,R+C.6{  
"'9[c"Iz  
String sHeader; wU $j/~L  
QKAt%"1&  
+#wh`9[wBt  
for(int i=1;;i++) Up*.z\|'y  
{ gQ8FjL6?  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @TqqF:c7  
//Utility.log(in.readLine()); {wS)M  
sHeader=httpConnection.getHeaderFieldKey(i); MEled:i  
if(sHeader!=null) R>CIEL  
{ \[CPI`yQe  
if(sHeader.equals("Content-Length")) q2U8]V U)  
{ Kc,=J?Ob  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KhFw%Z0s<  
break; wusj;v4C4M  
} KJQW))%e  
} iQ7S*s+l5O  
else K4`)srd  
break; ,+mH1#-3  
} {OBV+}#  
} 9irT}e  
catch(IOException e){e.printStackTrace ();} -w3KBlo  
catch(Exception e){e.printStackTrace ();} \])-Bp ,  
or)v:4PXW  
f*HEw  
Utility.log(nFileLength); piPx8jT`F  
u}~jNV  
7{fOo%(7  
return nFileLength; ]A%S&q  
} -rXo}I,VI  
"$6 .L^9W  
W}0cM9 g  
//保存下载信息(文件指针位置) `rQDX<?  
private void write_nPos() 7JL*y\'  
{ 5+yT{,(5  
try{  8-.jf  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6%Ws>H4@|  
output.writeInt(nStartPos.length); :3h'Hr  
for(int i=0;i<nStartPos.length;i++) E|`JmfLQu  
{ fx#Krr @  
// output.writeLong(nPos); x } X1 O)  
output.writeLong(fileSplitterFetch.nStartPos); )/4xR]  
output.writeLong(fileSplitterFetch.nEndPos); 7~H.\4HB  
} T:?01?m  
output.close(); 8-clL\bm  
} sQ05wAv  
catch(IOException e){e.printStackTrace ();} _ W +  
catch(Exception e){e.printStackTrace ();} ?K>=>bS^h  
} FsTl@zN  
>^|( AzS  
Dc;zgLLL  
//读取保存的下载信息(文件指针位置) wB0K e  
private void read_nPos() *v6 j7<H  
{ K2gg"#ft?  
try{ 0n('F  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HgfeSH  
int nCount = input.readInt(); PD$@.pib  
nStartPos = new long[nCount]; `k.Nphx~%  
nEndPos = new long[nCount]; PEIf)**0N  
for(int i=0;i<nStartPos.length;i++) _G1C5nkDl4  
{ DwBKqhu  
nStartPos = input.readLong(); s;NPY  
nEndPos = input.readLong(); x=jS=3$8  
} @Z{!T)#}j  
input.close(); ?VaAVxd29  
} tLc 9-  
catch(IOException e){e.printStackTrace ();} DuzJQ Sv  
catch(Exception e){e.printStackTrace ();} #OE]'k Ss  
} p^/6Rb"e  
Z<M?_<3  
Zwm2T3@e  
private void processErrorCode(int nErrorCode) B!iz=+RNC1  
{ !W?6,i-]  
System.err.println("Error Code : " + nErrorCode); U) B^R  
} D qh rg;  
5$;#=WAY  
G j9WUv[P  
//停止文件下载 l:?w{'i$  
public void siteStop() | bWvQdN  
{ ;wF 0s  
bStop = true; -Uu65m~:{k  
for(int i=0;i<nStartPos.length;i++) 8e{S(FZ7Ed  
fileSplitterFetch.splitterStop(); yWkg4  
p%?m|(4f  
c^a D r  
} ']cRSj.  
} i<ug("/  
//负责部分文件的抓取 ,rZp(moj  
**FileSplitterFetch.java hNWZ1r~_  
*/ \cKY{(E  
package NetFox; ;kv/(veQ1<  
f:_mrzz  
[Kc"L+H\  
import java.io.*; $T%~t@Cv1  
import java.net.*; b!hs|emo;  
zFpM\{`[g  
/6@~XO) w  
public class FileSplitterFetch extends Thread { M,V~oc5  
: #om6}   
B>=NE.ulUL  
String sURL; //File URL XNd%3rm,  
long nStartPos; //File Snippet Start Position KDQqN]rg  
long nEndPos; //File Snippet End Position 08 $y1;  
int nThreadID; //Thread's ID -<MA\iSP  
boolean bDownOver = false; //Downing is over $22_>OsA  
boolean bStop = false; //Stop identical @_ Q  
FileAccessI fileAccessI = null; //File Access interface C 7e  
YrRD3P.P  
`$hna{e^n  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5&QDZnsl  
{ +q NX/F  
this.sURL = sURL; t!S ja  
this.nStartPos = nStart; ML9nfB^z!  
this.nEndPos = nEnd; E` O@UW@  
nThreadID = id; w4UaWT1J  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H,I k&{@j  
} I]dt1iXu_{  
Nd] w I|>  
FK~FC:K  
public void run() O wJZ?j& )  
{ <.6bni )  
while(nStartPos < nEndPos && !bStop) gs?=yNL  
{ ^qgOgu  
)08mG_&atL  
pD )$O}  
try{ U! xOJ  
URL url = new URL(sURL); ImnN&[Cu  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4PsJs<u  
httpConnection.setRequestProperty("User-Agent","NetFox"); s1/:Ts[3i  
String sProperty = "bytes="+nStartPos+"-"; ?oKY"C8/  
httpConnection.setRequestProperty("RANGE",sProperty); |}YeQl  
Utility.log(sProperty); Q \E [py  
&F xw19[G  
'i5V6yB  
InputStream input = httpConnection.getInputStream(); c/bIt  
//logResponseHead(httpConnection); `tZ-8f  
X Nm%O  
O F|3y~z  
byte[] b = new byte[1024]; K$K6,54y  
int nRead;  <m7T`5+  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R,'` A.Kk  
{ 2:>|zmh_  
nStartPos += fileAccessI.write(b,0,nRead); Q, 1TD 2)h  
//if(nThreadID == 1) FSp57W$  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4Em$L]7   
} @}Y,A~   
B > sTM  
Fo0dz  
Utility.log("Thread " + nThreadID + " is over!"); $u`v k|\R  
bDownOver = true; :vqfWK6mv  
//nPos = fileAccessI.write (b,0,nRead); YH%aPsi  
} HS% P  
catch(Exception e){e.printStackTrace ();} @fML.AT  
} n%"0%A  
} w N-np3k  
k~<b~VcU  
/<\B8^yQ  
//打印回应的头信息 { 4(E @  
public void logResponseHead(HttpURLConnection con) Gxj3/&]^Y  
{ ?uq7K"B  
for(int i=1;;i++) ?[|T"bE5[  
{ 6tKm'`^z4  
String header=con.getHeaderFieldKey(i); j |N8"8"  
if(header!=null) I`O)I&KH  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t mCm54  
Utility.log(header+" : "+con.getHeaderField(header)); e!:/enQo  
else m)]A$*`<  
break; D)u 9Y  
} lQnl6j  
} b.<>CG'  
DKcg  
pX nY=  
public void splitterStop() K1F,M9 0]  
{ 2`-yzm  
bStop = true; vw'`t6  
} gx*rxid  
7:Jyu/*]  
J:{$\m'  
} T vEN0RV2  
P [.BK  
q $Hg\ {c  
/* _-vf<QO]  
**FileAccess.java fCA/   
*//文件访问(定位,写) ~}c`r4  
package NetFox; E>BP b  
import java.io.*; | Q Y_ci  
k#4%d1O}  
ON(H7  
public class FileAccessI implements Serializable{ 6Q&*V7EO  
j:yQP# U  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "iCR68e  
RandomAccessFile oSavedFile; &*I\~;1  
long nPos; 09f:%!^u  
<eObQ[mQ  
yMQuM :d  
public FileAccessI() throws IOException :y?xS  
{ 6~ *w~U  
this("",0); q/o|uAq  
} 5aF03+ko  
 Yfk){1  
CvCk#:@HM  
public FileAccessI(String sName,long nPos) throws IOException b6IYo!3  
{ RP 2MtP"M  
oSavedFile = new RandomAccessFile(sName,"rw"); "d a%@Zy  
this.nPos = nPos; [e2sUO0~r  
oSavedFile.seek(nPos); iY=M67V  
} -%&_LE9ZtS  
'L*nC T;  
|g5B==KI  
public synchronized int write(byte[] b,int nStart,int nLen) |(gq:O  
{ U/ncD F%C  
int n = -1; c2}?[\U]  
try{ x?J- {6k  
oSavedFile.write(b,nStart,nLen); `?P k~7  
n = nLen; 73$^y)AvY  
} ZQT14.$L  
catch(IOException e) Gy9+-7"V  
{ la ~T)U7  
e.printStackTrace (); |kvom 4T  
} Y[AL!h  
wVvk{tS  
Zho d%n3  
return n; SRl:+!@.  
} <RmI)g>'_^  
K2T&U$ ,  
Epm\ =s  
} #zC_;u$  
.:tAZZ  
\(t.|  
/* AL/q6PWi  
**SiteInfoBean.java .6%-Il  
*/ [&n2 yt  
package NetFox; @ 8yV15!  
;z;O}<8s  
hKw4[wB]  
public class SiteInfoBean { \ajy%$;$}  
^Bw2y&nN  
Cf`s:A5<J  
private String sSiteURL; //Site's URL =6b^j]1  
private String sFilePath; //Saved File's Path 8kQ >M  
private String sFileName; //Saved File's Name <d,Qi.G4  
private int nSplitter; //Count of Splited Downloading File Z~^)B8  
1 dT1DcZ  
.P\wE";  
public SiteInfoBean() l~,5)*T  
{//nSplitter的缺省值为5 YC#N],#  
//default value of nSplitter is 5 <6`_Xr7)  
this("","","",5); w-?_U7'  
} n7`R+4/s  
Bk&ry)`gD  
q/,>UtRr  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NF <|3|  
{ v*'dA^Q  
sSiteURL= sURL; Al="ss&2  
sFilePath = sPath; 7A|n*'[T>  
sFileName = sName; z{U2K '  
this.nSplitter = nSpiltter; dieGLA<5_X  
=Jfo=`da  
N;e d_!  
} !Mp.jE  
H%`Ja('"p  
62~8>71;'  
public String getSSiteURL() F$P8"q+  
{ Y.&nxT95=  
return sSiteURL; &U%AVD[  
} Su99A.w  
-ju&"L B  
!, Y1FC  
public void setSSiteURL(String value) /1ZRjf^  
{ x5_V5A/@LU  
sSiteURL = value; .}Va~[0j  
} lB9 9J"A  
R7u&`  
+jQHf-l  
public String getSFilePath()  }t}y  
{ {\3ZmF  
return sFilePath; ^6R?UG;6  
} x"q!=&>f  
F}p)Q$0  
` 6a  
public void setSFilePath(String value) <7-:flQz~  
{ c:(Xk zj  
sFilePath = value; g{wOq{7V  
} Q-<N)K$F(4  
J{ fTx@?(  
SPfz/ q{  
public String getSFileName() ,@1rP55  
{ ,MH/lQq%  
return sFileName; ~JhH ,E  
} [\eh$r\   
~n9x ,  
'/l<\b/E  
public void setSFileName(String value) _Q)rI%A2  
{ MYyV{W*T>  
sFileName = value; 1.29%O8V_  
} o~<ith$A*  
/>^sGB  
}7)iLfi  
public int getNSplitter() w)}' {]P"c  
{ L\;n[,.  
return nSplitter; ;ED` 7  
} _{$eOwB  
{v CB$@/o  
'x/pV5[hQ  
public void setNSplitter(int nCount) .8[*`%K>  
{ zsM3 [2E*  
nSplitter = nCount; n{'LF #4l  
} T$ w`=7  
} FYe#x]ue  
i`k{}!F  
E}-Y!,v^  
/* ,%Go.3i[  
**Utility.java ZQ@ Ul  
*/ o'Rr2,lVi  
package NetFox; y}5:CZ  
/[V}   
wlC7;u  
public class Utility { u7>{#]  
fX:=_c   
T~D2rt\  
public Utility() /+ yIcE(&3  
{ ,M?K3lG\g[  
|[+/ ]Y  
X}f u $2  
} J ?y0R X  
/TEE<\"  
//线程睡眠 zEBUR%9  
public static void sleep(int nSecond) g.,_E4L  
{ 5Z]]xR[  
try{ Ns2<wl-  
Thread.sleep(nSecond); B!j7vXM2  
} yiO/0nMp  
catch(Exception e) EX"o9'  
{ 59k[A~)~  
e.printStackTrace (); OyG#  
} |~]@hs~  
} r,8~qHbOT  
lnQfpa8j  
//日志 +{b3A@f|F  
public static void log(String sMsg) :iEIo7B  
{ d_] sV4[  
System.err.println(sMsg); OAiSE`  
} bmP2nD6  
k1_" }B5  
e8,!x9%J  
public static void log(int sMsg) nhImO@Q:  
{ JqTR4[`Z\  
System.err.println(sMsg); B;Dl2k^L  
} :k/Z|  
} han S8  
{b,#l]v  
n4A#T#D!t3  
/* o,yZ1"  
**TestMethod.java w f""=;  
*/ Nc_Qd4<[@G  
package NetFox; X%R)  
"lnI@t{o  
$ISx0l~  
public class TestMethod { ~{00moN"m  
I&Z+FL&@f  
@.8FVF  
public TestMethod() XGcl9FaO}  
{ ///xx/weblogic60b2_win.exe 'z$!9ufY,  
try{ P ~rTuj  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q&`if O  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p%#=OtkC  
SiteFileFetch fileFetch = new SiteFileFetch(bean); rp_Aw  
fileFetch.start(); VlFhfOR6t  
} OhiY <  
catch(Exception e){e.printStackTrace ();} qBF}-N_  
)u>/:  
"NvB@>S  
} fqm-?vy}  
zW:r7 P.  
:Oh*Q(>  
public static void main(String[] args) e3=-7FU  
{ <d~IdK'\x  
new TestMethod(); VpyqVbx1  
} /;;$9O9  
} Z"N}f ,  
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