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http断点续传简单实现(java)

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/* sS9%3i/>  
**SiteFileFetch.java +EkW>$  
*/ N4wA#\-  
package NetFox; B+"g2Y  
import java.io.*; pbLGe'  
import java.net.*; )yj:PY]  
BJ5}GX!  
CVQB"L  
public class SiteFileFetch extends Thread { Uu'dv#4Iw  
Gx'TkU=  
iM5vrz`n  
SiteInfoBean siteInfoBean = null; //文件信息Bean <kbyZXV@K  
long[] nStartPos; //开始位置 2f,2rW^i  
long[] nEndPos; //结束位置 Fm3t'^SqF  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 .=<$S#x^Hb  
long nFileLength; //文件长度 8\Hr5FqB(  
boolean bFirst = true; //是否第一次取文件 XUS vhr$|  
boolean bStop = false; //停止标志 SlaDt  
File tmpFile; //文件下载的临时信息 Phs-(3  
DataOutputStream output; //输出到文件的输出流 |/T43ADW  
sbS~N*{E  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 'jjb[{g^}}  
public SiteFileFetch(SiteInfoBean bean) throws IOException v>m n/a  
{ RiR:69xwR*  
siteInfoBean = bean; \ZH&LPAY  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 4["&O=:d  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); E\th%q,mG  
if(tmpFile.exists ()) ]'h; {;ug  
{ 8C7Z{@A&#  
bFirst = false; _Qd,VE 8u  
read_nPos(); P8I*dvu _  
} y%cO#P@  
else IIz0m3';+  
{ #YK5WTn5  
nStartPos = new long[bean.getNSplitter()]; 2Z/K(J"&J  
nEndPos = new long[bean.getNSplitter()]; shgAhx  
} =6T 4>rP  
tju|UhP3  
M1!pQC_9  
7r 0,> 3"  
} .}`hCt08  
A3{0q>CC  
)=^w3y  
public void run() jbmTmh1q  
{ ga0'zo9K  
//获得文件长度 XL5Es:"+?S  
//分割文件 f3tv3>p  
//实例FileSplitterFetch cAuY4RV  
//启动FileSplitterFetch线程 %f ju G  
//等待子线程返回 N "Wqy  
try{ K_/B?h  
if(bFirst) {nMAm/kyj  
{ ;4#D,zlO^  
nFileLength = getFileSize(); y,Q5; $w8  
if(nFileLength == -1) e@]Wh)  
{ vO@s$qi  
System.err.println("File Length is not known!"); _GoVx=t   
} r)T[(D'Tm-  
else if(nFileLength == -2) (pR.Abq  
{ m7qqY  
System.err.println("File is not access!"); ,|T7hTn=  
} $u9]yiY.{  
else b=[?b+  
{ =VP=|g  
for(int i=0;i<nStartPos.length;i++) 0GXO&rCG  
{ 8E^@yZo{  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ]MTbW=*}ED  
} 5g ;ac~g  
for(int i=0;i<nEndPos.length-1;i++) /VTM 9)u  
{ 8v92N g7  
nEndPos = nStartPos[i+1]; [rY T  
} &#m"/g7w4N  
nEndPos[nEndPos.length-1] = nFileLength; 2#5,MP~r  
} tj1JB%  
} E^Gg '1  
`,Vv["^PB  
<vc`^Q&4B  
//启动子线程 #Gf+=G  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M8;lLcgu.  
for(int i=0;i<nStartPos.length;i++) xFF r  
{ 3Rv7Qx  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {rH9grb  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HZ"Evl|n  
nStartPos,nEndPos,i); kODK@w V-  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8Jr?ZDf`  
fileSplitterFetch.start(); d^D i*&X  
} LXfCmc9|Z  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pa]"iZz  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5z/Er".P  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i%{X9!*%TX  
nEndPos = " + nFileLength); sq0 PBEqq  
// fileSplitterFetch[nPos.length-1].start(); ]]iPEm"@  
L2z2}U=<  
9@VO+E$7L  
//等待子线程结束 P9Q2gVGAO{  
//int count = 0; (!K_Fy@  
//是否结束while循环 ^>$P)=O:v  
boolean breakWhile = false; ^HA %q8| n  
U9d:@9Y  
oR#:Nt X@  
while(!bStop) H=MCjh&$q  
{ %b!-~ Y.  
write_nPos(); le>Wm&E  
Utility.sleep(500); ) M<vAUF  
breakWhile = true; $&P?l=UG  
MBr:?PE7  
{bNXedZ\  
for(int i=0;i<nStartPos.length;i++) ]`=X'fED  
{ S01wwZ  
if(!fileSplitterFetch.bDownOver) h5zVGr  
{ %"$@%"8;3  
breakWhile = false; -e@!  
break; )9nElb2  
} !Jfs?Hy  
} \l#>dq"Y  
if(breakWhile) *wbZ;rfF  
break; sKaE-sbJY  
W  0[N0c  
/\d$/~BFi  
//count++; $a;]_Y  
//if(count>4) xyHejE}  
// siteStop(); adEJk  
} q }C+tn"\  
\>/M .2  
-`c :}m  
System.err.println("文件下载结束!"); xycH~ ?  
} |BU+:+  
catch(Exception e){e.printStackTrace ();} y6HuN  
} D$e B ,~  
J]/}ojW3  
u62)QJE  
//获得文件长度 @Cq? :o<  
public long getFileSize() bMoAD.}  
{ 5"Kx9n|  
int nFileLength = -1; _Tm0x>EM  
try{ [\ )Ge  
URL url = new URL(siteInfoBean.getSSiteURL()); @]CF&: P A  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I=DLPgzO9  
httpConnection.setRequestProperty("User-Agent","NetFox"); dx_6X!=.J  
l0]d  
{OMg d3%14  
int responseCode=httpConnection.getResponseCode(); ),^eA  
if(responseCode>=400) w2gf&Lc\  
{ W=}Okq)x9I  
processErrorCode(responseCode); XFZ~ #DT&  
return -2; //-2 represent access is error B33$ u3d  
} <|6%9@  
y7u^zH6wj  
WV<tyx9Z  
String sHeader; _uxPx21g}  
+RZ~LA \+  
6)RbPPeE  
for(int i=1;;i++) P<dy3 ;  
{ i\}:hU-U  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J@"utY6N  
//Utility.log(in.readLine()); IfdI|ya  
sHeader=httpConnection.getHeaderFieldKey(i); 2i=H"('G)+  
if(sHeader!=null) dXvt6kF  
{ ~XM[>M\qB  
if(sHeader.equals("Content-Length")) JyBp-ii  
{ FY0%XW  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %FkLQ+v/<  
break; $ACx*e%  
} RNJ FSD.  
} ,32xcj}j)r  
else ks(SjEF  
break; a=}*mF[ug  
} Wsz0yHD[`  
} *dE^-dm#  
catch(IOException e){e.printStackTrace ();} D> ef  
catch(Exception e){e.printStackTrace ();} -$8.3\6h  
D9ufoa&ua  
mX# "+X|  
Utility.log(nFileLength); LgqGVh3\s  
$n=lsDnhQ  
HD`>-E#  
return nFileLength; 3Kq`<B~%  
} M].8HwC+  
w<wV]F*  
,{}#8r`+*  
//保存下载信息(文件指针位置) =yi OJyx  
private void write_nPos() >>'C :7+Y  
{ Q\_{d0 0  
try{ 5 9 2;W-y  
output = new DataOutputStream(new FileOutputStream(tmpFile)); x"B' zP  
output.writeInt(nStartPos.length); v|t{1[C  
for(int i=0;i<nStartPos.length;i++) ISqfU]>[  
{ 'ig, ATY  
// output.writeLong(nPos); |7F*MP  
output.writeLong(fileSplitterFetch.nStartPos); 649 !=  
output.writeLong(fileSplitterFetch.nEndPos); [Eq<":)  
} a+z2Zd!u\x  
output.close(); /p`&;/V|  
} ? Nj)6_&  
catch(IOException e){e.printStackTrace ();} zmFws-+A  
catch(Exception e){e.printStackTrace ();} mV\$q@sII  
} n'w,n1z7  
&y. dmW  
)C]x?R([m  
//读取保存的下载信息(文件指针位置) ?[1SiJT  
private void read_nPos() .Ao0;:;(2-  
{ )iE"Tl  
try{ D'i6",Z>  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !C&%T]  
int nCount = input.readInt(); 'CV^M(o'9  
nStartPos = new long[nCount]; 7>.OVh<  
nEndPos = new long[nCount]; J\`^:tcG  
for(int i=0;i<nStartPos.length;i++) I0w%8bs  
{ KCqqJ}G  
nStartPos = input.readLong(); &d^=s iL  
nEndPos = input.readLong(); S7sb7c'4 k  
} ^X? D#\  
input.close(); szq+@2:  
} YMzBAf  
catch(IOException e){e.printStackTrace ();} (F5ttQPh  
catch(Exception e){e.printStackTrace ();} o}D![/  
} otriif@+Z  
Da,Tav%b  
VWa|Y@Dc]  
private void processErrorCode(int nErrorCode) B@cz ?%]  
{ \+B?}P8N*l  
System.err.println("Error Code : " + nErrorCode); WmVVR>0V|  
} l)Mh2lA,=  
&?<AwtNN  
I'_v{k5ZI  
//停止文件下载 lo:~aJ8  
public void siteStop() f%Ke8'&  
{ d6b.zP  
bStop = true; /~hbOs/ L  
for(int i=0;i<nStartPos.length;i++) lX;mhJj!  
fileSplitterFetch.splitterStop(); g [L  
e-6(F4  
myvh@@N  
} kK?zVH-!  
} " i`8l.Lc  
//负责部分文件的抓取 6VR[)T%  
**FileSplitterFetch.java 'lQYJ0  
*/ L8P 36]>  
package NetFox; l9Pu&M?5  
K-@bwB7~s  
Bl4 dhBZoO  
import java.io.*; jgRCs.6  
import java.net.*; 9ECS,r*B  
chLeq  
#s^s_8#&e  
public class FileSplitterFetch extends Thread { .<w)Bmh  
:~-i&KNk  
<!!nI%NC  
String sURL; //File URL AU`OESSI  
long nStartPos; //File Snippet Start Position NbDda/7ki  
long nEndPos; //File Snippet End Position B9W/bJ6%  
int nThreadID; //Thread's ID jtLn j@,  
boolean bDownOver = false; //Downing is over .0 X$rX=  
boolean bStop = false; //Stop identical $rB!Ex{@ac  
FileAccessI fileAccessI = null; //File Access interface FO^24p  
8MQ bLj'H  
?N _)>&b  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1 ypjyu  
{ ,\>g  
this.sURL = sURL; m3"c (L`B  
this.nStartPos = nStart; I~k=3,7<  
this.nEndPos = nEnd; sL mW\\kA>  
nThreadID = id; sD2Qm  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T#N80BH[  
} 6vWii)O.D  
l#ygb|=x  
Ou!)1UFI  
public void run() +{^'i P  
{ FvA|1c  
while(nStartPos < nEndPos && !bStop) =W |vOfy  
{ Bxt_a.LthH  
Gl"wEL*  
w= B  
try{ v?{vg?vI  
URL url = new URL(sURL); vVdxi9yk  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !xH,y  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8E=vR 8  
String sProperty = "bytes="+nStartPos+"-"; ~=Fk/  
httpConnection.setRequestProperty("RANGE",sProperty); o[imNy~~  
Utility.log(sProperty); *V<)p%l.  
#4lHaFq  
Sy:K:Z|[U  
InputStream input = httpConnection.getInputStream(); \`&xprqAw  
//logResponseHead(httpConnection); qs "s/$  
"V:XhBG?  
@21u I{  
byte[] b = new byte[1024]; n }TTq6B  
int nRead; KG-UW  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yq!CWXZ2  
{ x6jm -n  
nStartPos += fileAccessI.write(b,0,nRead); O/nqNQ?<  
//if(nThreadID == 1) WEps.]s  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7Z VVR*n|  
} ^`/V i  
z 3Zu C{  
65uZ LsQ  
Utility.log("Thread " + nThreadID + " is over!"); >*Sv0#  
bDownOver = true; ?3n=m%W,J*  
//nPos = fileAccessI.write (b,0,nRead); j#CuR7m  
} 0NVG"-Q  
catch(Exception e){e.printStackTrace ();} & 8zk3  
} ~xP Szf  
} 2k%Bl+I  
fO0- N>W'P  
Q4#\{" N!  
//打印回应的头信息 Cx$9#3\  
public void logResponseHead(HttpURLConnection con) zkH<aLRB  
{ <.: 5Vx(Aw  
for(int i=1;;i++) T3 =)F%  
{ gq=0L:  
String header=con.getHeaderFieldKey(i); 69N1 mP  
if(header!=null) {E3;r7  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4 3}qaf[  
Utility.log(header+" : "+con.getHeaderField(header)); TeOFAIU  
else #@IQlqJfY7  
break; M_yZR^;^-  
} o@Dk%LxP  
} VOD1xWrb  
#d3[uF]OmW  
L!`*R)I45  
public void splitterStop() :Xb*m85y  
{ % E<FB;h  
bStop = true; =#7s+d-  
} ;]|m((15G  
T@2f&Un^  
Ufyxw5u5F  
} S^*(ALFPj  
}Ox2olUX  
avF&F  
/* *9\oD~2Y  
**FileAccess.java e,PQ)1  
*//文件访问(定位,写) NHst7$Y<  
package NetFox; =f/avGX  
import java.io.*; wI|bBfd(  
6,sRavs  
7N&3FER  
public class FileAccessI implements Serializable{ ,:\zXESy4  
ZYpD8u6U  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节  ] I N -  
RandomAccessFile oSavedFile; aTmX!!  
long nPos; BN bb&]  
DR#3njjEC  
;tZ}i4Ud  
public FileAccessI() throws IOException lk5_s@V l  
{ &@Ji+  
this("",0); J~PTVR  
} /jn:e"0~  
Br?++\  
&k {t0>  
public FileAccessI(String sName,long nPos) throws IOException ?Vb=4B{~  
{ 5cv, >{~5  
oSavedFile = new RandomAccessFile(sName,"rw"); t/4/G']W  
this.nPos = nPos; zXA= se0U  
oSavedFile.seek(nPos); lUm}nsp=X  
} 0:nt#n~_  
U/~Zk@3j  
^$^Vd@t>a  
public synchronized int write(byte[] b,int nStart,int nLen) #oS  
{ >Kqj{/SWK  
int n = -1; eFeCS{LV+  
try{ l%3Q=c  
oSavedFile.write(b,nStart,nLen); 60SenHKles  
n = nLen; w^vK7Z 1$  
} M zA  
catch(IOException e) xfZ9&g  
{ rSzXa4m(  
e.printStackTrace ();  Q}`2Y^.  
} h_}BmJh_  
lqwJ F &  
ce-m)o/  
return n; %QlBFl0a  
} +=lcN~U2  
omDi<-  
#6#BSZ E  
} =&<$I  
&dHm!b  
pu m9x)y1  
/* RI< Yg#   
**SiteInfoBean.java 5<>R dLo  
*/ Xj&~N;Ysb  
package NetFox; D=Yag!1  
LxYM "_1A;  
e&VR>VJEA  
public class SiteInfoBean { T[2f6[#[_  
WG!;,~f>o  
~dX@5+Gd  
private String sSiteURL; //Site's URL Z!BQtICs  
private String sFilePath; //Saved File's Path sfBjA  
private String sFileName; //Saved File's Name /A`zy  
private int nSplitter; //Count of Splited Downloading File =<27qj  
Eo3Aak o  
z jNjmC!W  
public SiteInfoBean() Hi 0df3t  
{//nSplitter的缺省值为5  ]9l%  
//default value of nSplitter is 5 $9u  
this("","","",5); "vHAp55B{  
} %BP)m(S7  
e"8m+]  
"oGM> @q=B  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pkMON}"mj  
{ x;b+gIz*  
sSiteURL= sURL; lPSDY&`P  
sFilePath = sPath; }R] }@i~i  
sFileName = sName; $oBZe>s .  
this.nSplitter = nSpiltter; "a_D]D(d5  
XQoT},C  
7Mb t*[n  
} ""KN?qh9  
)|1JcnNSa  
!/lY q;$R  
public String getSSiteURL() oL/^[TXjH  
{ H\>I&gC'  
return sSiteURL; A2FU}Ym0=  
} #YMp,i  
^T1-dw(  
blkJm9]v  
public void setSSiteURL(String value) ~0$F V  
{ >WS& w;G  
sSiteURL = value; NqfDY  
} g.sV$.T2K  
=id $  
:[rKSA]@  
public String getSFilePath() $Lbe5d?\  
{ 0\<-R  
return sFilePath; aC6b})^  
} JBJ7k19;  
~O7(0RsCN  
9<r}s  
public void setSFilePath(String value) -"tgEC\tD  
{ -ZON']|<}k  
sFilePath = value; YD.^\E4o  
} 1^>g>bn_"  
%hb5C 4q  
"4AQpD  
public String getSFileName() "8 mulE,  
{ QYb?;Z  
return sFileName; Bj[/ tQ  
} |6Z M xY  
=8 D4:Ds  
F|K4zhK  
public void setSFileName(String value) +E[)@;T  
{ :P1c>:j[  
sFileName = value; bbkI}d%(Ng  
} Ax*~[$$~%  
z$5C(!)  
.O.R  
public int getNSplitter() E\N=p&g$  
{ vp9<.*h  
return nSplitter; ?0%TE\I8  
} LkB!:+v |B  
/~5YTe( F  
.u?$h0u5  
public void setNSplitter(int nCount) x7@HPf  
{ ,LO-!\L  
nSplitter = nCount; mcG$V0D <{  
} cN>i3}fq  
} W-QPO  
5/ju it  
,RO(k4  
/* >MrU^t  
**Utility.java IW_D$pq  
*/ (W!$6+GT  
package NetFox; VrxH6Y  
Acv{XnB  
R  |%  
public class Utility { Z?mg1;Q  
A$6b=2hc>  
Af<>O$$6  
public Utility() n82Q.M-H  
{ V~Lq, oth  
D|:sSld @  
f|0QN#$  
} LS;anNk@.}  
]l%.X7M9  
//线程睡眠 Ti'kn{ Zv  
public static void sleep(int nSecond) vDvGT<d  
{ <DS6-y  
try{ 3>Snd9Q  
Thread.sleep(nSecond); n<*]`do,w  
} N@)~j+Pz  
catch(Exception e) 3fTI&2:  
{ 3kY4V*9@-  
e.printStackTrace (); NkI:  
} ] '/]j  
} hM w`e  
Am4(WXVQ  
//日志 p\ S3A(  
public static void log(String sMsg) x~eEaD5m%J  
{ W<o0Z OO  
System.err.println(sMsg); eS:e#>(  
} DA~ELje^j  
|vzWSm  
nUHVPuQ/'T  
public static void log(int sMsg) & jvG]>CS'  
{ EQC  
System.err.println(sMsg); GY xI$y0:  
} ze N!*VG  
} Iq \oB  
uD5yw #`  
G9Tix\SpF  
/* 12dW:#[  
**TestMethod.java x$DJ  
*/ faX#KRpfd  
package NetFox; 2"mj=}y6  
7+4"+CA  
o#/iR]3  
public class TestMethod { 1H7Q[ 2E  
^#se4qQ  
mC(t;{  
public TestMethod() DjvgKy=Jr_  
{ ///xx/weblogic60b2_win.exe 38i,\@p`9$  
try{ k]pD3.QJ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v"~I( kf$  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u_=y,~s  
SiteFileFetch fileFetch = new SiteFileFetch(bean); s;$TX304  
fileFetch.start(); pUGfm  
} Z]\^.x9S  
catch(Exception e){e.printStackTrace ();} =A 6O}0z  
d<nB=r!*  
/j@ `aG(a  
} {`CWzk?  
~')t1Ay s  
>Fk `h=Wd  
public static void main(String[] args) |9Ks13?Ck  
{ Qp&yS U8  
new TestMethod(); Uy|=A7Ad c  
} wJ*-K-  
} w{x(YVS H  
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