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http断点续传简单实现(java)

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/* hX_p5a1t  
**SiteFileFetch.java -$)Et|  
*/ A C^[3  
package NetFox; pHvE`s"Ea  
import java.io.*; vQ/\BN  
import java.net.*; *_QHtZG  
o3yqG#dA  
1hviT&  
public class SiteFileFetch extends Thread { 7:L~n(QpP  
:'dc=C  
4:@|q:DR  
SiteInfoBean siteInfoBean = null; //文件信息Bean \!QF9dP4  
long[] nStartPos; //开始位置 :b ;1P@W<  
long[] nEndPos; //结束位置 oPy zk7{  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 _;q-+"6L;  
long nFileLength; //文件长度 12PE{Mut  
boolean bFirst = true; //是否第一次取文件 X{xJ*T y'  
boolean bStop = false; //停止标志 mG~y8nUtp  
File tmpFile; //文件下载的临时信息 t60/f&A#7H  
DataOutputStream output; //输出到文件的输出流 w)eQ'6Vu  
/>[6uvy#Q  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) % 9/)  
public SiteFileFetch(SiteInfoBean bean) throws IOException {@ y,  
{ ^R7zLHU;  
siteInfoBean = bean; H27Oq8  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); i 9tJHeSm  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); wDhcHB  
if(tmpFile.exists ()) 'h^DI`  
{ $JB:rozE  
bFirst = false; G`#gV"PlC  
read_nPos();  DiQkT R  
}  GQ0(&I  
else W79A4l<  
{ c '+r[rSn1  
nStartPos = new long[bean.getNSplitter()]; ;]M67ma7C  
nEndPos = new long[bean.getNSplitter()]; 'D"K`Vw  
} R[9PFMn  
\ui^ d  
YaZt+WA  
eH!|MHe  
} RpK,ixbtA+  
m=.7f9  
OEE{JVeI  
public void run() M y"!j,Up  
{ !J=;Z9  
//获得文件长度 WQLL[{mhS  
//分割文件 TJ[jZuT:  
//实例FileSplitterFetch 0*;9CH=BE  
//启动FileSplitterFetch线程 :5K ~/=6x  
//等待子线程返回 f76|  
try{ 6>BDA?  
if(bFirst) kw^Dp[8X  
{ @!a]qAt  
nFileLength = getFileSize(); T7,Gf({  
if(nFileLength == -1) v~2XGm  
{ q AVfbcb  
System.err.println("File Length is not known!"); inv{dg/2  
} /9+A97{  
else if(nFileLength == -2) A Wh* <H  
{ lZA>L, \d  
System.err.println("File is not access!"); aho<w+l@  
} HA.NZkq.tV  
else EOnp!]Y  
{ ?> MoV5  
for(int i=0;i<nStartPos.length;i++) YeExjC  
{ `?o1cf A  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); l&sO?P[ /  
} Xf_tj:eO~  
for(int i=0;i<nEndPos.length-1;i++) 5-5(`OZ{'  
{ 1xdESorX(  
nEndPos = nStartPos[i+1]; _IKP{WNB  
} E"1 ;i  
nEndPos[nEndPos.length-1] = nFileLength; 9MtJo.A  
} S7NnC4)=-f  
} Bx}0E  
h>^jq{yu  
.xz,pn}  
//启动子线程 Xq^y<[  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N]s7/s  
for(int i=0;i<nStartPos.length;i++) $|cp;~ 1  
{ &Rl3y\ r  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K!D_PxV  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;vv!qBl|@  
nStartPos,nEndPos,i); \, %o>M'  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8/>wgY  
fileSplitterFetch.start(); gLxT6v5wk.  
} *L4]\wf  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _czbUl  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O^R:_vb3I  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]~ #+ b>  
nEndPos = " + nFileLength); 61+pryW%g  
// fileSplitterFetch[nPos.length-1].start(); K* _{Rs0P  
_> |R-vQ8  
V:F+HMBk  
//等待子线程结束 Ef_F#X0#  
//int count = 0; L=$?q/=-  
//是否结束while循环 -M1~iOb  
boolean breakWhile = false; c6Yf"~TD0  
csFJ5  
1IF'>*  
while(!bStop) CDnR  
{ J+cAS/MYX  
write_nPos(); {Ukc D+.Y  
Utility.sleep(500); }[KDE{,V  
breakWhile = true; 6& &}P79  
zh{@? k  
l)i &ATvCE  
for(int i=0;i<nStartPos.length;i++) Q/3tg  
{  *_ {l  
if(!fileSplitterFetch.bDownOver) |>IUtUg\  
{ 0?6 If+AC  
breakWhile = false; :?$Sb8OuIL  
break; oc3dd"8}@  
} [DotS\p!z  
} u>t|X}JH  
if(breakWhile) @`IXu$Wm(  
break; '!+ P{  
gI^L 9jE7  
(DG@<K,6  
//count++; \f /!  
//if(count>4) M|[@znzR<  
// siteStop(); h+B'_ `(  
}  \8>  
0\EpH[m}-  
k%Ma4_Z  
System.err.println("文件下载结束!"); wuBlFUSg  
} z<yNG/M1>U  
catch(Exception e){e.printStackTrace ();} *w'q  
} Q3NPwM  
wr3_Bf3]  
xs2,t*  
//获得文件长度 j[m_qohd7  
public long getFileSize() IDGQIg  
{ |5}rX!wS4  
int nFileLength = -1; wO2V%v^bp  
try{ |<j,Tr1[  
URL url = new URL(siteInfoBean.getSSiteURL()); 08Pt(kzNA  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H-/; l54E  
httpConnection.setRequestProperty("User-Agent","NetFox"); 6m, KL5>W  
Ism^hyL  
S+) l[0  
int responseCode=httpConnection.getResponseCode(); YM #  
if(responseCode>=400) Qq,i  
{ 6?1s`{yy  
processErrorCode(responseCode); l)tTg+:  
return -2; //-2 represent access is error 9*}iBs  
} &\J?[>EJ.  
V-D}U$fw  
9SRfjS{7  
String sHeader; u( V  
[K/O5_  
NCowt|#t  
for(int i=1;;i++) YVQ_tCC_!  
{ la G$v-r  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TIcd _>TW  
//Utility.log(in.readLine()); ZQ,fm`y\  
sHeader=httpConnection.getHeaderFieldKey(i); #dva0%-1  
if(sHeader!=null) /<3;0~#){  
{ |eH wp  
if(sHeader.equals("Content-Length")) g9yaNelDh)  
{ 0[n c7)sW  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JC c N>DtP  
break; Hv8SYQ|  
} ,s1&O`  
} $$haVY&  
else zAeGkP~K  
break; 9">zdFC'  
} fOa6,  
} kZV^F*7  
catch(IOException e){e.printStackTrace ();} |?OdV<5C  
catch(Exception e){e.printStackTrace ();} fH{9]TU_:  
Zi 2o  
1%$d D2  
Utility.log(nFileLength); OOEV-=  
v-P8WFjca  
89LpklD  
return nFileLength; ]]el|  
} E S#rs="  
$x?NNS_ "J  
?8 SK\{9r6  
//保存下载信息(文件指针位置) AuoxZ?V  
private void write_nPos() DJm oW  
{ ayV6m  
try{ >;&Gz-lm  
output = new DataOutputStream(new FileOutputStream(tmpFile)); |HrM_h<X  
output.writeInt(nStartPos.length); ;EgzC^2e  
for(int i=0;i<nStartPos.length;i++) 6OfdD.y  
{ t9G}Yd[T  
// output.writeLong(nPos); kP7a:(P_g  
output.writeLong(fileSplitterFetch.nStartPos); 7cIC&(h5  
output.writeLong(fileSplitterFetch.nEndPos); i LF^%!:X%  
}  uY.=4l  
output.close(); v#RW{kI  
} 285_|!.Y  
catch(IOException e){e.printStackTrace ();} w- UKMW9"  
catch(Exception e){e.printStackTrace ();} /h/6&R0l  
} 1|o$X  
sCVI 2S!L  
;*y|8od B  
//读取保存的下载信息(文件指针位置) RXGHD19]  
private void read_nPos() 6!ZVd#OM%  
{ \.c]kG>k-  
try{ M6J/mOVx5  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); zL9VR;q  
int nCount = input.readInt(); ~}h^38  
nStartPos = new long[nCount]; ~_'0]P\  
nEndPos = new long[nCount]; Y.q>EUSH  
for(int i=0;i<nStartPos.length;i++)  KR&s?  
{ dSwm|kIa  
nStartPos = input.readLong();  M{] e5+  
nEndPos = input.readLong(); 2< p{z  
} I^WIa"u_  
input.close(); fs&,w  
} ]\OWZ{T'j  
catch(IOException e){e.printStackTrace ();} W@l+ciZ_  
catch(Exception e){e.printStackTrace ();} 3@&bxYXm  
} o>2e !7  
c\M#5+1j  
6G'<[gL j  
private void processErrorCode(int nErrorCode) {]=v]O |,  
{ Q4X7Iu:  
System.err.println("Error Code : " + nErrorCode); Xad*I ulj  
} HeCcF+  
XdcG0D^  
9ftN8Svw  
//停止文件下载 mV<i JZh  
public void siteStop() , 7Xqte  
{ *9J1$Wa  
bStop = true; hL0]R,t;'  
for(int i=0;i<nStartPos.length;i++) ,E&Bn8L~O  
fileSplitterFetch.splitterStop(); u,f A!  
prZ55MS.  
#Rc5c+/(  
} eK9TAW  
} -n$ewV  
//负责部分文件的抓取 CD}Ns  
**FileSplitterFetch.java Yb}w;F8(  
*/ 3w Z(+<4i  
package NetFox; i|%5  
Kh)F yV  
BBvZeG $Y  
import java.io.*; L!gDFZr  
import java.net.*; jPnO@ H1  
z!:'V]  
y?>#t^  
public class FileSplitterFetch extends Thread { 27>a#vCT  
co/7lsW  
=N_,l'U\^  
String sURL; //File URL 9RxO7K  
long nStartPos; //File Snippet Start Position "IG+V:{ou  
long nEndPos; //File Snippet End Position =O,JAR"ug  
int nThreadID; //Thread's ID uArR\k(  
boolean bDownOver = false; //Downing is over hY+R'9  
boolean bStop = false; //Stop identical _9NVE|c;  
FileAccessI fileAccessI = null; //File Access interface H>.B99vp  
>dk 9f}7-  
('t kZt%8  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >!}`%pk(  
{  QsOhz  
this.sURL = sURL; =E y`M#t;  
this.nStartPos = nStart; n>P! u71  
this.nEndPos = nEnd; Noh?^@T`Ov  
nThreadID = id; vBNZ<L\|a  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x5OC;OQc  
} 6 mO"  
|) Pi6Y  
t8& q9$  
public void run() Jf)3< ~G  
{ :tM?%=Q  
while(nStartPos < nEndPos && !bStop) b{RqwV5P  
{ pc H<gF(k  
^mg*;8e Ga  
yG&2UqX  
try{ 8Mu;U3cIW  
URL url = new URL(sURL); YsP/p-  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }>&KUl  
httpConnection.setRequestProperty("User-Agent","NetFox"); nJJs% @y  
String sProperty = "bytes="+nStartPos+"-"; pUCK-rL  
httpConnection.setRequestProperty("RANGE",sProperty); ( KTnJZ  
Utility.log(sProperty); ioV_oR9I  
<C<`J{X0  
iq6a|XGi  
InputStream input = httpConnection.getInputStream(); xMI+5b8  
//logResponseHead(httpConnection); 0Q~@F3N-\>  
O"*`'D|hK  
ni6r{eSQ  
byte[] b = new byte[1024]; 2yKz-"E  
int nRead; z<pJYpxH  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \cQ .|S  
{ R#(G%66   
nStartPos += fileAccessI.write(b,0,nRead); %y"J8;U  
//if(nThreadID == 1) vG Vd  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "+|L_iuNQ  
} s&'BM~WI  
!gH 9ay  
~O;y?]U  
Utility.log("Thread " + nThreadID + " is over!"); hazq#J!  
bDownOver = true; Pl+xH%U+?  
//nPos = fileAccessI.write (b,0,nRead); 6:?rlh  
} )"`!AerJ  
catch(Exception e){e.printStackTrace ();} 4:mCXP,x  
} |NrrTN?>  
} 0xpx(T[  
TfRGA (+#  
^Y04qeRd  
//打印回应的头信息 4_LQ?U>$  
public void logResponseHead(HttpURLConnection con) #Qbl=o4  
{ '#Dg8/r!  
for(int i=1;;i++) 4/*H.Fl  
{ ,P6=~q3k  
String header=con.getHeaderFieldKey(i); 0oU=RbC  
if(header!=null) Lw*]EG|?  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )%Ru#}1X6  
Utility.log(header+" : "+con.getHeaderField(header)); Cd]/  
else GBP-V66  
break; ._ CP% R  
} <7n]Ai@Y  
} EO)%UrWnC  
+.Bmkim  
&uM^0eM  
public void splitterStop() GXX+}=b7qO  
{ .Q>!B?)  
bStop = true; VC-;S7k  
} (j&A",^^S  
(/h5zCc/v  
'v&}(  
} vR>o}%`  
z`$J_CjY  
wJG$c-(\0  
/* eW8[I'v_&  
**FileAccess.java n56;m`IU  
*//文件访问(定位,写) I*\^,ow  
package NetFox; ml u 3K  
import java.io.*; ~ 3T,&?r  
&L4 q10-N  
.px:e)iW  
public class FileAccessI implements Serializable{ ULBg {e?l8  
UQT'6* !  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .q;ED`G  
RandomAccessFile oSavedFile; Hl7:*]l7b  
long nPos; |L:Cn J  
zAScRg$:?  
>V;,#5F_  
public FileAccessI() throws IOException qv+R:YYOq  
{ Bjj<\8 ^M  
this("",0); Z=+03  
} NZXjE$<Vr  
Lz4eh WntO  
cd.brM  
public FileAccessI(String sName,long nPos) throws IOException .%xzT J=!  
{ MZv\ C  
oSavedFile = new RandomAccessFile(sName,"rw"); i$UQbd  
this.nPos = nPos; HJhH-\{@  
oSavedFile.seek(nPos); S>_27r{  
} 1BTIJ Gw  
9dKul,c  
7#2j>G{?]v  
public synchronized int write(byte[] b,int nStart,int nLen) ?Zcj}e.r  
{ \pY^^ l*  
int n = -1; -50AX1h31:  
try{ ;Zut@z4\  
oSavedFile.write(b,nStart,nLen); 'Ud| Ex@A9  
n = nLen; 3/goCg  
} >3D7tK(  
catch(IOException e) d"T Ht}  
{ Q9>U1]\  
e.printStackTrace (); p1O6+hRio  
} V@ :20m  
+=3CL2{An  
9 $l>\.6  
return n; raB+,Oi$G  
} 0[a}n6X Tk  
P-Su5F  
2x} 6\t  
} /c-nE3+rn  
eD;6okdP  
}e{qW  
/* K|^wc$  
**SiteInfoBean.java xtfRrX^  
*/ bEH de*q(  
package NetFox; 8^yJqAXK  
=@r--E  
qfL-r,XS`F  
public class SiteInfoBean { d*]Ew=^L  
pyB~M9Bp/  
t[C1z  
private String sSiteURL; //Site's URL d'HOpJE  
private String sFilePath; //Saved File's Path |. C1|J'Z  
private String sFileName; //Saved File's Name %|"Qi]c d  
private int nSplitter; //Count of Splited Downloading File r%=[},JQ  
_p}xZD\?,  
zFhgE*5  
public SiteInfoBean() KSqTY>%fnv  
{//nSplitter的缺省值为5 2(#Ks's?  
//default value of nSplitter is 5 Dy9\O77>  
this("","","",5); <8o(CA\  
} :nGMtF  
)pgrl  
-|_ir-j  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) eti `O  
{ WS0JS'  
sSiteURL= sURL; TT}]wZ  
sFilePath = sPath; p2pAvlNoF  
sFileName = sName; e>H:/24  
this.nSplitter = nSpiltter; Q GPw2Q  
;4~U,+Av  
|:q/Dt@  
} $aP(|!g  
.YcN S%  
vzR=>0#  
public String getSSiteURL() PEXq:TA  
{ %5B%KCCN  
return sSiteURL; j4.&l3  
} Np,2j KF(  
=,/D/v$m'2  
#$1$T  
public void setSSiteURL(String value) 4E3g,%9u  
{ 9`Q@'( m  
sSiteURL = value; IB$7`7  
} jj&s} _75  
tJZc/]%`H  
d/U."V}  
public String getSFilePath() ; st\I  
{ u?0d[mC  
return sFilePath; ]> G&jd7  
} igkz2SI  
M7dU@Ag  
i@$*Csj\9*  
public void setSFilePath(String value) LI W*4r!  
{ iS: #o>  
sFilePath = value; P%>?[9!Nt  
} v,1F-- v  
$ |<m9CW  
>S#ul?  
public String getSFileName() (4+1lOd  
{ a39hP*  
return sFileName; \V%_hl  
} 's%q  
CEtR[Cu  
0D [@u3W  
public void setSFileName(String value) By((,QpB  
{ `/:cfP\  
sFileName = value; Ot9V< D6h  
} f(:1yl\a  
3N4.$#>#9@  
([k7hUP  
public int getNSplitter() 3LK%1+)4  
{ N6/T#UVns  
return nSplitter; $99R|^  
} ?d-70pm  
JLm @Ag  
"4 k-dj  
public void setNSplitter(int nCount) ?]!vRmZ;  
{ ^Kq|ID AP  
nSplitter = nCount; A WJWtUa  
} {d!Y3+I%G  
} IgX4.]W5  
At9X]t  
}T(z4P3  
/* ;VzMU ;j  
**Utility.java +Ui_ O  
*/ |nxdB&1n  
package NetFox; 5 2Hqu>  
v\A.Tyy  
R@`rT*lJ  
public class Utility { =_-C%<4  
j\2[H^   
n[" 9|  
public Utility() []}N  
{ y-+G wa3  
@$U e$  
vDE |sT  
} P Jo  
Sb"2Im>  
//线程睡眠 &Ocu#Cb  
public static void sleep(int nSecond) J!p<oW)a!  
{ 0HibY[_PbD  
try{ BQNp$]5s  
Thread.sleep(nSecond); S/Oxr%H  
} \< 65??P  
catch(Exception e) H5M#q6`H6  
{ 3H8Al  
e.printStackTrace (); <Dm Tj$  
} ^.HWkS`e  
} <GZhH:  
.6T4z7I  
//日志 8pe0$r`b  
public static void log(String sMsg) !Q)3-u  
{ m&El)  
System.err.println(sMsg); 3|eUy_d3  
} 9g@NcJ]  
-Ktwo_ V*  
z7=fDe -  
public static void log(int sMsg) >t #\&|9I  
{ p;->hn~D'5  
System.err.println(sMsg); 5gK~('9'?1  
} Eo=HNe  
} o# {#r@,i  
kL;t8{n  
{ymb\$f  
/* r{ @ `o@q  
**TestMethod.java pxplWP,  
*/ HdCk!Fv  
package NetFox; !0jq6[&  
n;OHH{E{  
A{`]& K1u  
public class TestMethod { 6>B \|  
K&S@F!#g  
S0xIvzS  
public TestMethod() 'Y)/~\FI  
{ ///xx/weblogic60b2_win.exe h48 bb.p2  
try{ E .;io*0  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F#1kZ@nq  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Oz>io\P94  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^!uO(B&  
fileFetch.start(); 2"M_sL  
} t2.juoI(  
catch(Exception e){e.printStackTrace ();} pqfT\Kb>  
NG)7G   
78w4IICk  
} -\,VGudM}  
gKQ@!U U8  
3"tg+DncC  
public static void main(String[] args) 3- )kwy6L  
{ 9::YR;NY  
new TestMethod(); { _X#fq0}  
} vnZ/tF  
} (`mOB6j  
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