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http断点续传简单实现(java)

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/* `~XksyT  
**SiteFileFetch.java j iKHx_9P  
*/ #^}H)>jWy  
package NetFox; oU\]#e^  
import java.io.*; Rqe. =+Qs  
import java.net.*; xfRp_;l+R  
^KhJBM/Z  
Y`g oV  
public class SiteFileFetch extends Thread { wgFX')l:  
SkjG}  
2uj .*  
SiteInfoBean siteInfoBean = null; //文件信息Bean HE&)N clY  
long[] nStartPos; //开始位置 Fm`*j/rq  
long[] nEndPos; //结束位置 N@d~gE&^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 =u2 z3$  
long nFileLength; //文件长度 od=hCQ1 >  
boolean bFirst = true; //是否第一次取文件 orjtwF>^  
boolean bStop = false; //停止标志 p9"dm{  
File tmpFile; //文件下载的临时信息 UT;%I_i!'  
DataOutputStream output; //输出到文件的输出流 o `YBz~2  
!v8R(  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) WARiw[  
public SiteFileFetch(SiteInfoBean bean) throws IOException s#^0[ Rt  
{ tVG;A&\,6  
siteInfoBean = bean; i-|N6J  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 7 yE\,  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); [* <x)  
if(tmpFile.exists ()) S~/2Bw!2  
{ :E9pdx+  
bFirst = false; /EjXyrn2  
read_nPos(); coXg]bUKo  
} ?t 'V5$k\  
else Im6gWDdq@6  
{ o;@~uU  
nStartPos = new long[bean.getNSplitter()]; pX &bX_F{  
nEndPos = new long[bean.getNSplitter()]; MT!Y!*-5  
} O>L,G)g  
wO]e%BTO  
3t-STk?  
&~*](Ma  
} (WHg B0{  
OlT8pG5Oa  
L\#YFf  
public void run() >6S7#)0T  
{ 5aaM;45C  
//获得文件长度 +jhzE%  
//分割文件 >h aihT  
//实例FileSplitterFetch 9J/[7TzSZ  
//启动FileSplitterFetch线程 YE`Y t  
//等待子线程返回 7qqzL_d>  
try{ }uma<b  
if(bFirst) Y%;J/4dd  
{ .Y6v#VI  
nFileLength = getFileSize(); S<7!<]F-  
if(nFileLength == -1) e]VW\ 6J&  
{ c^I^jg2v  
System.err.println("File Length is not known!"); Bz/ba *  
} 7(}'jZ  
else if(nFileLength == -2) 'vNju1sfk  
{ Krae^z9R  
System.err.println("File is not access!"); SZH`-xb!+5  
} /Bt!xSI  
else GL?b!4xx  
{ @)d_zWE  
for(int i=0;i<nStartPos.length;i++) Hs)Cf)8u  
{ o8X_uKEI  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); $ 64up!  
} >B6* `3v  
for(int i=0;i<nEndPos.length-1;i++) ,ayEZ#4.m  
{ !=eNr<:V.  
nEndPos = nStartPos[i+1]; r#OPW7mhE  
} .e7tq\k  
nEndPos[nEndPos.length-1] = nFileLength; l qfTF  
} loIb}8  
} N# }A9t  
+j{Cfv$do  
=!t;e~^8]  
//启动子线程 x`g,>>&C  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H$Kc~#=  
for(int i=0;i<nStartPos.length;i++) :(]fC~G~  
{ H^|TV]^;N  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), + ,Krq 3P  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0!,uo\`  
nStartPos,nEndPos,i); 36Lkcda[  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =p_*lC%N  
fileSplitterFetch.start(); "}v.>L<P  
} ktrIi5B  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Go{,< gm  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i2Wvu3,D3-  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V22z-$cb  
nEndPos = " + nFileLength); xnMcxys~  
// fileSplitterFetch[nPos.length-1].start(); R ABw( b  
8)>x)T  
(ODwdN7;  
//等待子线程结束 JwbZ`Z*w  
//int count = 0; ]JkEf?;.  
//是否结束while循环 KAnV%j  
boolean breakWhile = false; jh/,G5RM9  
BP9#}{kE  
%rb$tKk  
while(!bStop) ~yJ2@2I  
{ d%|l)JF*5  
write_nPos(); b=r3WkB6  
Utility.sleep(500); X8ulaa  
breakWhile = true; d#E&,^@M  
}gQ2\6o2g  
Rq}lW.<r  
for(int i=0;i<nStartPos.length;i++) {3x>kRaKci  
{ o*)Sg6Yk  
if(!fileSplitterFetch.bDownOver) yn mjIQ  
{ -  ]wT  
breakWhile = false;  p?f\/  
break; [uU!\xe  
} '?Dxe B  
} ;~<To9O  
if(breakWhile) KFbB}oId  
break; 3'.@aMA@  
bVUIeX'  
n/skDx TE  
//count++; #B5,k|"/,M  
//if(count>4) %]Z4b;W[Y  
// siteStop(); 6 ]x?2P%  
} .yy-jf/  
qA GjR!=^  
]P3m=/w  
System.err.println("文件下载结束!"); ^i%S}VK  
} v\,N"X(,  
catch(Exception e){e.printStackTrace ();} eMRH*MyD  
} i#V(oSx  
Fs~(>w@  
0 cycnOd  
//获得文件长度 m}'_Poc  
public long getFileSize() XX/gS=NE#.  
{ ZHK>0>;  
int nFileLength = -1; ;Xt <\^e  
try{ % [$HX'Y  
URL url = new URL(siteInfoBean.getSSiteURL()); 7,SQz6]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !vnC-&G  
httpConnection.setRequestProperty("User-Agent","NetFox"); cR3d& /_,U  
a6LL]_&g  
\o!3TK"N  
int responseCode=httpConnection.getResponseCode(); #`u}#(  
if(responseCode>=400) 96^aI1:  
{ lndz  
processErrorCode(responseCode); N_T5sZ\  
return -2; //-2 represent access is error ~`AB-0t.u  
} w~u{"E$  
8Nzn%0(Q  
|4mvB2r  
String sHeader; g.&B8e  
Q!P%duO  
6axxyh%  
for(int i=1;;i++) \!\:p/f  
{ 0 SSdp<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b11I$b #  
//Utility.log(in.readLine()); K[y")ooE<j  
sHeader=httpConnection.getHeaderFieldKey(i); vR\E;V  
if(sHeader!=null) w||t3!M+n  
{ D<J'\mo  
if(sHeader.equals("Content-Length")) 8lV:-"+5  
{ t.ulG *  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M>i(p%  
break; ? uYO]!VC  
} ;NA5G:eQ  
} `9r{z;UQ  
else )5b_>Uy  
break; \( s `=(t  
} hTDGgSG^  
} ya&=UoI  
catch(IOException e){e.printStackTrace ();} >B{qPrmI  
catch(Exception e){e.printStackTrace ();} w<H Xe  
"\@J0 |ppb  
@4;'>yr(  
Utility.log(nFileLength); ?1ey$SSU]  
sLA.bp.O  
QDn_`c  
return nFileLength; E,m|E]WP  
}  ]ltCJq  
Z+ k) N  
aA4RC0'  
//保存下载信息(文件指针位置) j9k:!|(2'  
private void write_nPos() lW c[Q1  
{ nDvfb* \  
try{ sc]#T)xG  
output = new DataOutputStream(new FileOutputStream(tmpFile)); qefp3&ls  
output.writeInt(nStartPos.length); Gt*<Awn8  
for(int i=0;i<nStartPos.length;i++) :z8/iD y  
{ >3/ mV<g f  
// output.writeLong(nPos); 'f{13-# X@  
output.writeLong(fileSplitterFetch.nStartPos); \uTlwS  
output.writeLong(fileSplitterFetch.nEndPos); {LiJ=Ebt  
} c6F?#@?   
output.close(); C[,h!  
} ,&,%B|gT]  
catch(IOException e){e.printStackTrace ();} 1R}9k)JQ  
catch(Exception e){e.printStackTrace ();} n=-vOa%  
} (LK@w9)i;  
!U?C _  
X.#*+k3s0  
//读取保存的下载信息(文件指针位置) !ldEy#"X  
private void read_nPos() _qE9]mU  
{ F qJ`d2E  
try{ h1q 3}-  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -F/)-s6#!'  
int nCount = input.readInt(); jlb8<xIC]  
nStartPos = new long[nCount]; M;XU"8  
nEndPos = new long[nCount]; _kBmKE  
for(int i=0;i<nStartPos.length;i++) n}Z%-w$K#  
{ P\dfxR;8%  
nStartPos = input.readLong(); BW;@Gq@N  
nEndPos = input.readLong(); #!_4ZX  
} ulALGzPh  
input.close(); \'=svJ   
} P6%qNR/ x  
catch(IOException e){e.printStackTrace ();} $|7"9W}m*  
catch(Exception e){e.printStackTrace ();} VJ#ys _W  
} tfHr'Qy BC  
nrE.0Ue1  
b6S"&hs  
private void processErrorCode(int nErrorCode) ozsd6&z5l  
{ r } Wdj  
System.err.println("Error Code : " + nErrorCode); `}t5`:#k  
} NdJ]\>5oN,  
\ 3E%6L  
\#biwX  
//停止文件下载 8cfsl lI  
public void siteStop() yE N3/-S+  
{ I8i|tQz  
bStop = true; V #vkj  
for(int i=0;i<nStartPos.length;i++) /QS Nv  
fileSplitterFetch.splitterStop(); 5q4wREh  
+9LzDH  
j(I(0Yyh  
} %J6>Vc!ix=  
} Ox ,Rk  
//负责部分文件的抓取 [.l,#-vp  
**FileSplitterFetch.java Y|mtQ E?c  
*/ 0;a10b  
package NetFox; !JdZ0l  
0Bgj.?l  
a:P+HU:  
import java.io.*; \gT({XU?  
import java.net.*; q !}~c  
vZQraY nJ  
R,.qQF\*  
public class FileSplitterFetch extends Thread { R{H8@JLD  
 uWMSn   
.HTRvE`X  
String sURL; //File URL k_1;YO BF  
long nStartPos; //File Snippet Start Position BV<_1 WT}  
long nEndPos; //File Snippet End Position Foj|1zJS_  
int nThreadID; //Thread's ID maSVqG  
boolean bDownOver = false; //Downing is over UH&1QV  
boolean bStop = false; //Stop identical kb$Yc)+R4  
FileAccessI fileAccessI = null; //File Access interface <bJ|WS|  
"WY5Pzsi:  
V9KRA 1  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9Pvv6WyKy  
{ [#aJ- Uu  
this.sURL = sURL; \Dr( /n  
this.nStartPos = nStart; Md9y:)P@Y  
this.nEndPos = nEnd; b$Ei>%'/";  
nThreadID = id; y:zNf?6&  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B!x6N"  
} BQ,749^S  
 f^}n#  
OGH,K'l  
public void run() '4GN%xi  
{ BC#`S&R  
while(nStartPos < nEndPos && !bStop) :V6t5I'_  
{ ?;w`hA3ei  
\u6.*w5TI  
#3>jgluM'  
try{  ^0{t  
URL url = new URL(sURL); Kl?C[  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WOgkv(5KN  
httpConnection.setRequestProperty("User-Agent","NetFox"); Nj?Q{ztS  
String sProperty = "bytes="+nStartPos+"-"; E i2M~/  
httpConnection.setRequestProperty("RANGE",sProperty); #$ka.Pj  
Utility.log(sProperty); sWTa;Qi  
VeEa17g&  
,<7HLV  
InputStream input = httpConnection.getInputStream(); `p)U6J  
//logResponseHead(httpConnection); D0_CDdW%7  
/ZL6gRRA|  
 !Qsjn  
byte[] b = new byte[1024]; 3:w_49~: ~  
int nRead; |A|K);  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )yz)Fw|&  
{ Bs '=YK$  
nStartPos += fileAccessI.write(b,0,nRead); kTzO4s?  
//if(nThreadID == 1) [@pumH>  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `S3)uV]I  
} QX a2qxTc  
zk@s#_3ct  
x!7!)]h  
Utility.log("Thread " + nThreadID + " is over!"); mWP&N#vwh  
bDownOver = true; 6c>:h)?  
//nPos = fileAccessI.write (b,0,nRead); r0OP !u  
} ^VnnYtCRz  
catch(Exception e){e.printStackTrace ();} 71IM`eL=ED  
} ^IvQdVB  
} 0<<ATw$aQ  
9 %Vy,  
>CcDG  
//打印回应的头信息 c[3x>f0  
public void logResponseHead(HttpURLConnection con) klc$n07  
{ L[5U(`q[  
for(int i=1;;i++) 'aeuL1mz  
{ P~&J@8)c  
String header=con.getHeaderFieldKey(i); Aj/EaIq  
if(header!=null) 5)rN#_BKj  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :Ez*<;pF'  
Utility.log(header+" : "+con.getHeaderField(header)); }0/l48G  
else cl{mRt0  
break; F U L'=Xo  
} M`9|8f,!a  
} |<8Fa%!HHc  
1(i%nX<U  
_K!)0p  
public void splitterStop() 1'\s7P  
{ -) +B!"1  
bStop = true; }t|i1{%_  
} BNO+-ob-  
s`yg?CR`,  
N]ebKe  
} WXf[W  
LF{8hC[  
m}beT~FT_  
/* ^mut-@ N9  
**FileAccess.java !F Zg' 9  
*//文件访问(定位,写) C0^r]^$Z  
package NetFox; $EdL^Q2KAy  
import java.io.*; fU.z_ T[@  
(_N(K`4#W  
! P$[$W  
public class FileAccessI implements Serializable{ pz{ ]O_px  
&:}WfY!hX  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #g2&x sU  
RandomAccessFile oSavedFile; lG[j,MDs  
long nPos; (b1e!gJpy  
n0V^/j}  
Uu Zjf9}  
public FileAccessI() throws IOException S*76V"")  
{ +'VYqu/  
this("",0); 0hXx31JN N  
} >I;.q|T  
p%#'`*<a_  
w xa MdA  
public FileAccessI(String sName,long nPos) throws IOException 3".#nN  
{ D mky!Cp  
oSavedFile = new RandomAccessFile(sName,"rw"); l&Y'5k_R  
this.nPos = nPos; rodqa  
oSavedFile.seek(nPos); IF6-VFY:6  
} @ W,<8  
<<Z, 1{3F  
>$a;+v  
public synchronized int write(byte[] b,int nStart,int nLen) g<$2#c}  
{ I;UT; /E2  
int n = -1; Q^xk]~G$(  
try{ HHs!6`R$0c  
oSavedFile.write(b,nStart,nLen); e;|$nw-  
n = nLen; XBcbLF  
} B)P]C5KRD  
catch(IOException e) v5{2hCdt  
{ U+[ "b-c  
e.printStackTrace (); *q[;-E(fZ#  
} eq<!  
Jy('tfAHp  
hL}ZPHA  
return n; cT;Zz5  
} *|@386\  
$e  uI  
PY+4OZ$  
} Qf'g2 \  
)NqRu+j  
8NJT:6Q7l  
/* $(*>]PC+)  
**SiteInfoBean.java `'pAiu  
*/ a#9pN?~  
package NetFox; p|BoEITL  
%E [HMq<H  
U: )Gc  
public class SiteInfoBean { k7cY^&o  
^oW{N  
zW)Wt.svP  
private String sSiteURL; //Site's URL &$l#0?Kc^  
private String sFilePath; //Saved File's Path M23r/eg]  
private String sFileName; //Saved File's Name sN#ju5  
private int nSplitter; //Count of Splited Downloading File $>+g)  
kZi/2UA5Z  
dB:c2  
public SiteInfoBean() iHvWJ<"jR  
{//nSplitter的缺省值为5 MhB> bnWXR  
//default value of nSplitter is 5 (S?DKPnR  
this("","","",5); uotW[L9  
} }-u%6KZ   
cF?0=un  
)V_;]9<wt  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B$ho g_=s  
{ t-<BRnxhE  
sSiteURL= sURL; {lg iH+:  
sFilePath = sPath; ,]Xn9 W  
sFileName = sName; o-;/ x)  
this.nSplitter = nSpiltter; +F2X2e)g"  
|y+_BZ5  
x]3[0K5;  
} ]I zD`  
33&\E- Q>  
_c5*9')-)  
public String getSSiteURL() ,@Kn@%?$  
{ Hk(=_[S  
return sSiteURL; sNP ;  
} ( 5uSqw&U  
(Fq:G) $  
9b@yDq3hQ  
public void setSSiteURL(String value) tE-g]y3  
{ 1xh7KBr,  
sSiteURL = value; t% <y^Wa=  
} <$WS~tTz  
dep"$pys>  
j0(jXAc;UB  
public String getSFilePath() J(w FJg\/  
{ m - hZ5 i  
return sFilePath; 8%xBSob{j  
} 1-&L-c.  
?ks.M'@  
}6=)w@v  
public void setSFilePath(String value) A5%$<  
{ ,H^!G\  
sFilePath = value; brlbJFZ19  
} ED>a'y$f  
y*v|q=  
>7S@3,C3ke  
public String getSFileName() ]0j_yX  
{ !]RSG^%s{  
return sFileName; Nd{U|k3pL  
} a;M{ -G  
Fop +xR,Z  
,LxkdV  
public void setSFileName(String value) TU*EtE'g/  
{ bX` Gv+  
sFileName = value; &|db}\jT  
} 2% OAQ(  
()F {kM8  
1xkrh qq  
public int getNSplitter() ZmNNR 1%/  
{  p(8@  
return nSplitter; *c&|2EsZ  
} x}V&v?1{5  
^H{YLO  
U%[ye0@:  
public void setNSplitter(int nCount) lBAu@M  
{ m]vV.pwv  
nSplitter = nCount; fFWi 3.  
} Hrph>v  
} 6 .)Xeb"  
f fBd  
AQT_s9"0  
/* bovAFdHW  
**Utility.java L[,19 ;(  
*/ u]9\_{c]Q  
package NetFox; sowwXrECg@  
qMA-#  
*f`P7q*  
public class Utility { \g h |G  
_L$a[zH  
2CneRKQy  
public Utility() i. (Af$  
{ n|XheG7:  
<JU3sXl  
slUi)@b  
} -B&(& R  
gZ7R^] k  
//线程睡眠 UxzF5V5  
public static void sleep(int nSecond) 2Q5@2jT  
{ Hbd>sS  
try{ c;fLM`{*  
Thread.sleep(nSecond); 7v)p\#-  
} kc't  
catch(Exception e)  X0$q !  
{ v+W'0ymbnV  
e.printStackTrace (); N'R^gL  
} +*?l">?|F  
} }2Euz.0  
\=bKuP(it  
//日志 lw.[qP  
public static void log(String sMsg) ;l ZKgi8`  
{ Fb =uN   
System.err.println(sMsg); |?8nO.C~V  
} DL1nD5  
!4'Fz[RK  
v^8sL` F  
public static void log(int sMsg) UeLO`Ug0;  
{ @z{SDM  
System.err.println(sMsg); 7bihP@I !  
} yb ?Pyq.D  
} Hz2Sx1.i  
J'$NBws  
'xGhMgR;  
/* *Q/^ib9=  
**TestMethod.java /#H P;>!n  
*/ =\5WYC  
package NetFox; G[yzi  
hr6j+p:  
}&e HU  
public class TestMethod { MJ1qU}+]  
tZz%x?3G  
]rH[+t-  
public TestMethod() ?X@[ibH6  
{ ///xx/weblogic60b2_win.exe H?J:_1  
try{ _#6Q f  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9&AO  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ohp@ZJ!a?  
SiteFileFetch fileFetch = new SiteFileFetch(bean); _lwKa, }  
fileFetch.start(); a*U[;(  
} jTIG#J)  
catch(Exception e){e.printStackTrace ();} ~$5XiY8A  
*qy \%A  
9n{Y6I x:  
} dX@ic,?  
;M4[Liw~O  
c&',#.9  
public static void main(String[] args) L'? aoRj  
{ M-Efe_VRQc  
new TestMethod(); &um++ \  
} t~/:St  
} m1Ya  
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