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http断点续传简单实现(java)

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/* dk_! ~Z  
**SiteFileFetch.java rebWXz7  
*/ !a7YM4D  
package NetFox; AmX ~KK  
import java.io.*; CTf39R|7_  
import java.net.*; ,aU8. J_U  
THcX.%ToT  
B42qiV2/k  
public class SiteFileFetch extends Thread { P0l.sVqL  
*EF`s~  
:+v4,=fHy  
SiteInfoBean siteInfoBean = null; //文件信息Bean d:g0XP  
long[] nStartPos; //开始位置 2rrC y C  
long[] nEndPos; //结束位置 3Lm7{s?=Z-  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 u a_(wBipy  
long nFileLength; //文件长度 RwoAZ]Zg]  
boolean bFirst = true; //是否第一次取文件 mc|8t0+1`  
boolean bStop = false; //停止标志 L rhQG  
File tmpFile; //文件下载的临时信息 >@.:9}Z  
DataOutputStream output; //输出到文件的输出流 T1A/>\Ns  
bmw"-W^U[  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) xsRu~'f  
public SiteFileFetch(SiteInfoBean bean) throws IOException uC5W1LyI  
{ p&lT! 5P!A  
siteInfoBean = bean; PcEE@W9  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); jP )VTk_  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); /MbWS(RT  
if(tmpFile.exists ()) 1v'|%B;O  
{ K}!YXy h  
bFirst = false; XSktb k  
read_nPos(); L YMb)=u]  
} I6Oc`S!L  
else w^)_Fk3  
{ qFwAzW;"  
nStartPos = new long[bean.getNSplitter()]; {KqERS& g  
nEndPos = new long[bean.getNSplitter()]; xF`O ehVA  
} .tzQ hd>  
gezZYP)d  
d$PQb9Q+f  
Df}3^J~JX  
} "[2D&\$  
znNv;-q  
t}2M8ue(&  
public void run() r~;TId} #  
{ DC,]FmWs!+  
//获得文件长度 uE&2M>2  
//分割文件 F>"B7:P1:Q  
//实例FileSplitterFetch O/lu0acI  
//启动FileSplitterFetch线程 o(Q='kK  
//等待子线程返回 */ok]kX'  
try{ 43/!pW  
if(bFirst) BF(Kaf;<t.  
{ vve[.Lud'  
nFileLength = getFileSize(); Rqun}v}  
if(nFileLength == -1) }EJ't io]  
{ ~uweBp~O  
System.err.println("File Length is not known!"); Wq/0}W.  
} V w5@)l*f  
else if(nFileLength == -2) Y@'ahxF  
{ E )%r}4u>  
System.err.println("File is not access!"); "kg?Or.  
} FS6I?q#tQ  
else V6tUijz  
{ -"w&g0Z  
for(int i=0;i<nStartPos.length;i++) ^ZG 3{>  
{ 5dEek7wnf  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); rtk1 8U-  
}  4d )Q  
for(int i=0;i<nEndPos.length-1;i++) Kv#TJn  
{ T`r\yl}  
nEndPos = nStartPos[i+1]; gpe-)hD@R  
} zK ir  
nEndPos[nEndPos.length-1] = nFileLength; )! C|DSw  
} )jaNFJ 3  
} "(^1Dm$(  
OojQG  
M{M?#Q  
//启动子线程 ] KR\<MJK  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; = ms o1  
for(int i=0;i<nStartPos.length;i++) YLe$Vv735  
{ 6)Dp2  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #>(h!lT_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m~l[Y  
nStartPos,nEndPos,i); sp&)1?!M  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); * 57y.](w  
fileSplitterFetch.start(); 4I<U5@a  
} pk:2>sx/  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qC$h~Epp4  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9lCZ i?  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mp+lN:  
nEndPos = " + nFileLength); SBqx_4}  
// fileSplitterFetch[nPos.length-1].start(); T0Zv.  
]Qb85;0)  
Tq=OYJq5U  
//等待子线程结束 .~fAcc{Qj  
//int count = 0; VS_xC $X!S  
//是否结束while循环 w`F4.e  
boolean breakWhile = false; $ h<l  
x1nqhSaD  
c=A)_ZFg  
while(!bStop) LG3:V'|  
{ %$.]g  
write_nPos(); {Tym#  
Utility.sleep(500); }Qo:;&"3  
breakWhile = true; Dt p\ T|)  
iPoDesp  
(>gAnebN L  
for(int i=0;i<nStartPos.length;i++) PgF7ug%,@C  
{ 3~Vo]wv  
if(!fileSplitterFetch.bDownOver) 8I*WVa$l  
{ l~9P4 ,  
breakWhile = false; VvTs87  
break; .}zpvr8YP  
} M,nLPHgK  
} e.:SBXZ  
if(breakWhile) <xWBS/K  
break; @f wk  
!O~5<tA[#1  
|6}:n,KA.  
//count++; Sx%vJYH0  
//if(count>4) `:fc*n,*  
// siteStop(); :6Oh?y@  
} " O,TL *$  
Q\4nduQ  
"mm|0PUJ  
System.err.println("文件下载结束!"); 56R)631]p  
} -8r9DS -/W  
catch(Exception e){e.printStackTrace ();} ]rP'\a  
} eTp}*'$p  
dJ0qg_ U&  
MVpk/S%W  
//获得文件长度 y8.(filNB  
public long getFileSize() ,awp)@VG7  
{ CH/*MA  
int nFileLength = -1; NFQR  
try{ "L p"o  
URL url = new URL(siteInfoBean.getSSiteURL()); =Nj58l  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8+7=yN(  
httpConnection.setRequestProperty("User-Agent","NetFox"); fm%1vM$[J  
Cyw cJ  
VD*xhuy$k  
int responseCode=httpConnection.getResponseCode(); ?NL>xMA  
if(responseCode>=400) w/(hEF '  
{ ]8i2'x  
processErrorCode(responseCode); j 4B|ktf  
return -2; //-2 represent access is error ^YLpZoo  
} =_/,C  
? <.U,  
_+\hDV>v  
String sHeader; 5Se S^kJC  
iVKX *kqc  
~!w()v n  
for(int i=1;;i++) &E>zvRBQ  
{ 8I'Am"bc \  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J0hY~B~X  
//Utility.log(in.readLine()); Q*+_%n1 /  
sHeader=httpConnection.getHeaderFieldKey(i); 8VwByk8  
if(sHeader!=null) .RNr^*AQ  
{ *&vySyt  
if(sHeader.equals("Content-Length")) ul',!js?  
{ 1JU1XQi  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u,6 'yB'u  
break; /{~cUB,Um  
} S}rW=hO  
} -O ro$=%  
else ;S FmbZ%~  
break; 2_4m}T3   
} y ~ A]  
} Z-!W#   
catch(IOException e){e.printStackTrace ();} W1UG\d`2  
catch(Exception e){e.printStackTrace ();} \gE3wmSJ,  
y!9facg  
T F!Lp:  
Utility.log(nFileLength); `2Buf8|a,  
m*h, <,}-+  
q?=eD^]  
return nFileLength; K_J o^BZ  
} AID}NQ Qj_  
Xjal6e)[  
3eV(2  
//保存下载信息(文件指针位置) K%: :  
private void write_nPos() `3$S^|v  
{ wNuS'P_(:T  
try{ oy-Qy  
output = new DataOutputStream(new FileOutputStream(tmpFile)); a/.O, &3  
output.writeInt(nStartPos.length); eTc0u;{V  
for(int i=0;i<nStartPos.length;i++) )p MZ5|+X  
{ T~k5` ~\(  
// output.writeLong(nPos); NC; 4  
output.writeLong(fileSplitterFetch.nStartPos); P^%.7C  
output.writeLong(fileSplitterFetch.nEndPos); -4p^wNR  
} 1u\fLAXn  
output.close(); |4i,Vkfhe  
} $ V"~\h8  
catch(IOException e){e.printStackTrace ();}  _"ysJ&  
catch(Exception e){e.printStackTrace ();} \jdpL1  
} :B=p%C  
'\:?FQ C  
/hue]ZaQq  
//读取保存的下载信息(文件指针位置) *R*Tmo"  
private void read_nPos() Ah_'.r1<P9  
{ Cm;WQuv@  
try{ 8KpG0DC  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z,nRw/o  
int nCount = input.readInt(); ~>@Dn40  
nStartPos = new long[nCount]; .Lrdw3(  
nEndPos = new long[nCount]; V*U7-{ *a  
for(int i=0;i<nStartPos.length;i++) $cev,OW6]  
{ 9-+6Ed^2  
nStartPos = input.readLong(); x C'>W"pY  
nEndPos = input.readLong(); DVYY1!j<  
} ]?L?q2>&  
input.close(); a$I; L  
} $S$%avRX  
catch(IOException e){e.printStackTrace ();} Aa&3x~3+  
catch(Exception e){e.printStackTrace ();} 5Mb1==/R  
} c@{,&,vsj  
bQk5R._got  
r4O*0Q_  
private void processErrorCode(int nErrorCode) {y|y68y0+  
{ S ~lw5  
System.err.println("Error Code : " + nErrorCode); uU`zbh}]L.  
} (tEW#l'}  
S8" h9|  
EX8:B.z`57  
//停止文件下载 J#CF SG  
public void siteStop() wX7B&w8wV  
{ au8bEw&W  
bStop = true; .1MXQLy  
for(int i=0;i<nStartPos.length;i++) |pr~Ohz  
fileSplitterFetch.splitterStop(); 0[0</"K%1m  
^HKxaW9W  
`3r*Ae  
} 8oY0?|_Bx  
} 4qjY,QJ  
//负责部分文件的抓取 G%anot  
**FileSplitterFetch.java Y 3[<  
*/ WJ\YKXG  
package NetFox; 8 k+Ctk  
*#EyfMz-B  
!.iA^D//]  
import java.io.*; * Yov>lO  
import java.net.*; >k^=+  
)zt*am;  
52*zX 3  
public class FileSplitterFetch extends Thread { ^zqz$G#  
<?Fgm1=o  
v}-'L#6  
String sURL; //File URL z@&_3 Gl  
long nStartPos; //File Snippet Start Position R\yw9!ESd  
long nEndPos; //File Snippet End Position ms3Ec`i9  
int nThreadID; //Thread's ID vVKiE 6^  
boolean bDownOver = false; //Downing is over 1O9V Ej5  
boolean bStop = false; //Stop identical e )\s0#  
FileAccessI fileAccessI = null; //File Access interface +(r8SnRX  
jKQnox+=  
T:wd3^.CG  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eUqsvF}l!  
{ LP_ !g  
this.sURL = sURL; RXgi>Hz  
this.nStartPos = nStart; Q=~e|  
this.nEndPos = nEnd; Oa7`Y`6  
nThreadID = id; oHu0] XA  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w0moC9#$?  
} Z/hSH 0(~  
R^dAwt`.D  
2hf]XV\  
public void run()  2c!?!:s  
{ W3 2mAz;  
while(nStartPos < nEndPos && !bStop) Ik=KEOz  
{ I2|iqbX40Q  
~oT0h[<  
"S#0QH%5  
try{ ^#exs Xy  
URL url = new URL(sURL); sKjg)3Sl  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,_YCl09p(  
httpConnection.setRequestProperty("User-Agent","NetFox"); LUKdu&M  
String sProperty = "bytes="+nStartPos+"-";  UX2`x9  
httpConnection.setRequestProperty("RANGE",sProperty); sh}=#eb  
Utility.log(sProperty); kY xn5+~  
Vjj30f  
62%. ddM4  
InputStream input = httpConnection.getInputStream(); 6E@r9U  
//logResponseHead(httpConnection); s qac>v  
l[Ng8[R  
3j<] W  
byte[] b = new byte[1024]; &{y- }[~  
int nRead; ) #Y*]  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Uh?SDay  
{ T -C2V$1  
nStartPos += fileAccessI.write(b,0,nRead); T\8|Q @  
//if(nThreadID == 1) 5x4JDaG2  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E+>Qpy  
}  z{``v|K  
6!Ji-'\"  
;2)@NH  
Utility.log("Thread " + nThreadID + " is over!"); K-k;`s#  
bDownOver = true; v?!x,H$Qd  
//nPos = fileAccessI.write (b,0,nRead); 69r<Z  
} ![U|2x   
catch(Exception e){e.printStackTrace ();} bPOehvK/  
} -`iZBC50  
}  5ah]E  
o*I=6`j  
2HkP$;lED  
//打印回应的头信息 e}kEh+4  
public void logResponseHead(HttpURLConnection con) cl1h;w9s  
{ M*8Ef^-U`t  
for(int i=1;;i++) /S\P=lcb  
{ 1/6G&RB  
String header=con.getHeaderFieldKey(i); Bz9!a k~4  
if(header!=null) 8_8 R$ =V  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?J6J#{LRd  
Utility.log(header+" : "+con.getHeaderField(header)); Z!~~6Sq  
else CdatN$/*  
break; &'c1"%*%8>  
} >UZfi u  
} /V2 ^/`&;a  
z~L(kf4  
VCNg`6!x  
public void splitterStop() L!c7$M5xJ  
{ b!5W!vcK  
bStop = true; 5Ee%!Pk  
} \@GA;~x.b  
:=T+sT~  
&JtK<g  
} -+#\WB{AI  
<8+.v6DCd  
C:0Ra^i ?L  
/* DE^{8YX,  
**FileAccess.java K.",=\53  
*//文件访问(定位,写) M7fw/i  
package NetFox; *s S7^OZ*  
import java.io.*; %W+*)u72(  
; R&wr _%  
o.k eM4OQ  
public class FileAccessI implements Serializable{ UOy`N~\gh+  
O9dIobu4  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2u*o/L+  
RandomAccessFile oSavedFile; NK~j>>^;v  
long nPos; 3!,XR\`[  
} R;.~F  
3/@7$nV  
public FileAccessI() throws IOException bQr H8)  
{ ]j~V0 1p/e  
this("",0); 5|9,S  
} SLD%8:Zn  
]xCJ3.9  
-s,^_p{H  
public FileAccessI(String sName,long nPos) throws IOException !G 90oW  
{ `QnKal)  
oSavedFile = new RandomAccessFile(sName,"rw"); )d2 <;c  
this.nPos = nPos; k*w]a  
oSavedFile.seek(nPos); >hJ$~4?  
} |K,9EM3  
&Op, ?\   
vjhd|  
public synchronized int write(byte[] b,int nStart,int nLen) bT|a]b:  
{ /![S 3Ol  
int n = -1; *rXESw]BR  
try{ R/Mwq#xUb  
oSavedFile.write(b,nStart,nLen); ?nn`ud?f  
n = nLen; o6 'I%Gs  
} h*Rh:yCR>  
catch(IOException e) 7*r Q6rAP  
{ 3qXOsa7  
e.printStackTrace (); <_dyUiT$J  
} `kpX}cKK}  
X2}\i5{  
hJ (Q^Z  
return n; 1j`-lD  
} M$B9?N6  
_*>bf G  
+\fr3@Yc  
} E5~HH($b  
t>)iC)^u  
C\ZL*,%}  
/* Vl%AN;o  
**SiteInfoBean.java m.iCGX  
*/ rr>QG<i;G  
package NetFox; o8-BTq8  
{Kx eH7S  
w4Qqo(  
public class SiteInfoBean { j&6,%s-M`a  
mS p -  
*`mPPts}  
private String sSiteURL; //Site's URL zH0%; o}  
private String sFilePath; //Saved File's Path yM}}mypS  
private String sFileName; //Saved File's Name $3[IlQ?  
private int nSplitter; //Count of Splited Downloading File WS/^WxRY  
*p`0dvXG2  
/`Yy(?,  
public SiteInfoBean() 5Q#;4  
{//nSplitter的缺省值为5 w},' 1  
//default value of nSplitter is 5 DJ_,1F  
this("","","",5); # =V%S 2~  
} I= G%r/3  
ZR.1SA0x?O  
ng0IRJ:3  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w,bILv)  
{ /;-KWu+5=  
sSiteURL= sURL; |NJe4lw+?  
sFilePath = sPath; L(\sO=t  
sFileName = sName; &tB|l_p_-p  
this.nSplitter = nSpiltter; 4EQ7OGU  
MqGF~h|+  
|5 _bFB+&  
} bZHuEh2w  
;2Db/"`t  
bW(+Aw=O  
public String getSSiteURL() ,d(F|5 M:  
{ 8/,m8UOY  
return sSiteURL; uSLO"\zysX  
} }`8g0DPuD9  
h!5^d!2,  
~=h]r/b< U  
public void setSSiteURL(String value) %jdV8D#Q  
{ >ygyPl ;1s  
sSiteURL = value; r(h&=&T6  
} BIEc4k5(  
J~eY,n.6]  
M[}EVt~  
public String getSFilePath() q>/# P5V  
{ 8Y*SZTzV  
return sFilePath; Fh9%5-t:J  
} SlB,?R2  
qR4('  
^h{A AS>  
public void setSFilePath(String value) d"<Q}Ay  
{ ^.5 L\  
sFilePath = value; DQ :w9  
} )f-ux5  
0#lw?sv  
_QbLg"O  
public String getSFileName() mr6/d1af_  
{ F`S OF O  
return sFileName; 5 WSu  
} /ZqBO*]  
zWoPa,  
3v)v92;  
public void setSFileName(String value) +(0Fab8g  
{ 9r-]@6;  
sFileName = value; S8*VjG?T\  
} E/|]xKG  
sP$bp Z}  
W.iL!x.B@  
public int getNSplitter() R#i|n< x  
{ 0@d)DLM?  
return nSplitter; xx0s`5  
} [hTGWT3  
Vo}3E]  
|};]^5s9  
public void setNSplitter(int nCount) @P#uH5U  
{ %ANo^~8  
nSplitter = nCount; .yE!,^j.gB  
} AN7WMX  
} OLJb8kO  
$C0Nv Jf  
sUN>uroi !  
/* >8Wvz.Nq/  
**Utility.java JYL/p9K[I  
*/ n)uvN  
package NetFox; I'2:>44>I6  
=A={ Dpv[>  
C`+g:qT  
public class Utility { XIh2Y\33ys  
vn|u&}h  
OLUQjvnU  
public Utility() ,oX48Wg_+  
{ 4b=hFwr[?  
CZRrb84  
=Xh^@ OR  
} kF.!U/C  
G,M &z>ub0  
//线程睡眠 TWYz\Hmw  
public static void sleep(int nSecond) QLH&WF  
{ :'?%%P  
try{ h^^zR)EVb  
Thread.sleep(nSecond); 4[a?. .X  
} e`k6YO  
catch(Exception e) fL.;-  
{ =MDir$1Z  
e.printStackTrace (); ]UKKy2r.  
} jT"P$0sJAd  
} WXu:mv,'e  
eT1b88_  
//日志 `}.K@17  
public static void log(String sMsg) h=SQ]nV{  
{ } [}u5T`w>  
System.err.println(sMsg); 0cZyO$.  
} dl;~-'0  
p 2x OjS1  
Cj%SW <v|  
public static void log(int sMsg) #P*%FgROl  
{ @;kw6f:{d  
System.err.println(sMsg); pg~vteq5  
} ?g%5 d  
} E]w1!Ah M  
'Wjuv9)/  
Q:eIq<erY  
/* v1<gNb)`  
**TestMethod.java `bu3S }m7  
*/ Af1izS3  
package NetFox; Cnd70tbD )  
$'e;ScH  
rB;` &)-  
public class TestMethod { eO;i1>  
vF"<r,pg  
gP8Fe =]  
public TestMethod() 0fA42*s;  
{ ///xx/weblogic60b2_win.exe ~E-YXl9  
try{ ,!t1( H  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B04%4N.g"X  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4"1OtBU3  
SiteFileFetch fileFetch = new SiteFileFetch(bean); D}'g4Ag  
fileFetch.start(); mj5$ 2J  
} Ol H{!  
catch(Exception e){e.printStackTrace ();} c+?L?s`"  
},'hhj]O  
6cz%>@  
} =2uE\6Fl,  
(q`Jef  
5r"BavA  
public static void main(String[] args) u\=gps/Z  
{ !t "uNlN  
new TestMethod(); 11}sRu/  
} %AW5\ EX  
} K:yS24\ %  
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