http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); EG'[`<*h
} DfJ2PX}q
for(int i=0;i<nEndPos.length-1;i++) [LT^sb
{ 4@ILw
nEndPos = nStartPos[i+1]; GwsY-jf
} ;TQf5|R\K
nEndPos[nEndPos.length-1] = nFileLength; zWw2V}U!
} ;vhyhP.oM
} I4rPHZ|
aI zv
/|{,sWf2
//启动子线程 z!=P@b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; B bhfG64
for(int i=0;i<nStartPos.length;i++) Z>F^C}8f
{ \u`)kJ5o1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HDM<w+ZxX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1rw0sAuGy
nStartPos,nEndPos,i); [\)oo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IC/(R! Crj
fileSplitterFetch.start(); qv 3^5d
} ;S$Ll*f>D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JnD{J`:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <j}lp-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F9c`({6k
nEndPos = " + nFileLength); $ E1Tb{'
// fileSplitterFetch[nPos.length-1].start(); 3HG;!D~m;
dYFzye
`U!y&Q$,
//等待子线程结束 (%ew604X
//int count = 0; Ue5O9;y]u
//是否结束while循环 {hSGv
boolean breakWhile = false; {TSY|D2
|YJCWFbs8
@54*.q$
while(!bStop) #$S}3 o
{ VBoMT:#
write_nPos(); jdut4 nFc
Utility.sleep(500); cl[!`Z
breakWhile = true; Z{-Lc68
Df07y<>7Q
4FeEGySow
for(int i=0;i<nStartPos.length;i++) }m]q}r
{ ]rd/;kg.S
if(!fileSplitterFetch.bDownOver) _cJ[ FP1
{ =?}twC$
breakWhile = false; -=$2p0"R
break; <~Qi67I
} wjU.W5IR
} XaI;2fMGI
if(breakWhile) $Ptk|qFe
break; E+_&HG}a
OTvROJP
a^nAZ
//count++; S*W;%J5
//if(count>4) #5CI)4x0!
// siteStop(); d{+(Lpj^
} QezSJ io
85U.wpG
'E]A.3-Mt
System.err.println("文件下载结束！"); Iq'O
} w*LbH]l<-
catch(Exception e){e.printStackTrace ();} r((Tavn
} c,5n,i
AY2:[ 5cm
q|#MB7e/
//获得文件长度 e$l6gY
public long getFileSize() 4KpL>'Q=
{ WO</Q6+
int nFileLength = -1; a0_(eO-S
try{ ?T*";_o,B
URL url = new URL(siteInfoBean.getSSiteURL()); )q^ Bj$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;b~~s.+
httpConnection.setRequestProperty("User-Agent","NetFox"); @ RR\lZ
<)#kq1b?
-WR}m6yMr
int responseCode=httpConnection.getResponseCode(); PnWD}'0V
if(responseCode>=400) z]#hWfM4B:
{ "n?<2 wso
processErrorCode(responseCode); E20&hc5 8
return -2; //-2 represent access is error vZjZb(jlN
} #s"B-sWE
-CBD|fo[h
/8eW@IO.F
String sHeader; tHI*,
=HE m)
l1-HO
for(int i=1;;i++) Eb@MfL
{ $Ub}p[L
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 981!2*
//Utility.log(in.readLine()); MW@DXbKVl
sHeader=httpConnection.getHeaderFieldKey(i); ~775soN
if(sHeader!=null) 'j79GC0
{ \iZ1W
if(sHeader.equals("Content-Length")) *T4ge|zUc
{ epVH.u%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :kp0EiJ
break; T T"3^@
} X<xqT
} <xF?~7
else *i?.y*g
break; hEOJb @:R
} >eo8
} TNci.']
catch(IOException e){e.printStackTrace ();} \Da~p9T&
catch(Exception e){e.printStackTrace ();} :&$Xe1)i]
a;p6?kv
+{ab1))/
Utility.log(nFileLength); Gg+YfY_
,4Y sZ
Mcb<[~m
return nFileLength; ):E'`ZP!F
} }}s) +d
& =sayP
}rxFS <j
//保存下载信息（文件指针位置） * D3
private void write_nPos() +-k`x0v
{ 2o}8W7y
try{ -9Xw]I#QR
output = new DataOutputStream(new FileOutputStream(tmpFile)); *<3iEeO/R
output.writeInt(nStartPos.length); -AeHY'T
for(int i=0;i<nStartPos.length;i++) qq>44k\|)
{ ]eL~L_[G\
// output.writeLong(nPos); ndt8=6p
output.writeLong(fileSplitterFetch.nStartPos); )XZ,bz*jn
output.writeLong(fileSplitterFetch.nEndPos); ]=pWZ~A
} ,,2_/u\"/i
output.close(); +{bh
} T/3;NXe6E
catch(IOException e){e.printStackTrace ();} 6!o/~I#
catch(Exception e){e.printStackTrace ();} <sF!]R&4
} ,|>nF;.Y
m&{rBz0
QD6Z=>?S
//读取保存的下载信息（文件指针位置） F6h/0i
private void read_nPos() pe|\'<>i
{ .y(@Y6hO
try{ D`5: JR-{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r6/<&1[
int nCount = input.readInt(); ^&e;8d|f{
nStartPos = new long[nCount]; r]Z.`}Kkm
nEndPos = new long[nCount]; [kQ"6wh8
for(int i=0;i<nStartPos.length;i++) lK 9s0t'
{ !vi4* @:
nStartPos = input.readLong(); LIc*tsl
nEndPos = input.readLong(); gS0,')w
} H==X0
input.close(); +._f.BRmX.
} mRNHq3
catch(IOException e){e.printStackTrace ();} ZO]E@?Oav
catch(Exception e){e.printStackTrace ();} i,^>uf
} I-j(e)P(o_
4t"*)xy
:Fq2x_IUE
private void processErrorCode(int nErrorCode) 30:HRF(:
{ B&to&|jf
System.err.println("Error Code : " + nErrorCode); :a#|
} $=X!nQ& Z|
&FT5w T
&*h`b{]
//停止文件下载 #p;4:IT
public void siteStop() _ +u sn.
{ 6uv'r;U]
bStop = true; eU<]h>2
for(int i=0;i<nStartPos.length;i++) ajg7xF{l)
fileSplitterFetch.splitterStop(); XL%vO#YT
?^F*"+qI
_&6juBb
} S+4I[|T]Y
} HQjxJd5P
//负责部分文件的抓取 `Nxo0Q
**FileSplitterFetch.java {3_Ffsg`
*/ lUy*549,
package NetFox; m&;zLBA;
LL6ON }
6Vu}kK)
import java.io.*; aH~x7N6!
import java.net.*; D~t"9Z\
?ZD{e|:u
4@ydK
public class FileSplitterFetch extends Thread { Q)7L^
k1@ A'n
<%5-Pzp
String sURL; //File URL D:S6Mu
long nStartPos; //File Snippet Start Position H@OrX
long nEndPos; //File Snippet End Position D|8sjp4
int nThreadID; //Thread's ID -O5(%
boolean bDownOver = false; //Downing is over d[qEP6B
boolean bStop = false; //Stop identical 2*3B~"
FileAccessI fileAccessI = null; //File Access interface 8kn]_6:3i
8{U]ATx'(
Sj=69>m]5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vb80J<4
{ ?Pok-90
this.sURL = sURL; Wtzj;GJj
this.nStartPos = nStart; Xk$l-Zfse
this.nEndPos = nEnd; !<UEq`2
nThreadID = id; bl!f5ROS(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 N4JqW
} ^7^bA
`!>dbR&1
s5Bmv\e.i5
public void run() JWm^RQ
{ Bafz&#;Q'
while(nStartPos < nEndPos && !bStop) r&l*.C*
{ 9OO_Hp#|9
Kr}M>hF+|
PU/Br;2A
try{ IP4b[|ef
URL url = new URL(sURL); G:6$P%.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >Qbc(}w
httpConnection.setRequestProperty("User-Agent","NetFox"); lN`_0
String sProperty = "bytes="+nStartPos+"-"; ,B/p1^;.
httpConnection.setRequestProperty("RANGE",sProperty); -GkK[KCH
Utility.log(sProperty); RNrYT|
>a`zkl
QGCdeE$K
InputStream input = httpConnection.getInputStream(); +]~w ?^h
//logResponseHead(httpConnection); pQ-^T.'
E{]|jPdr
_I}L$
byte[] b = new byte[1024]; R_*D7|v
int nRead; pNf9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &)f++(i
{ R&|)y:bg|
nStartPos += fileAccessI.write(b,0,nRead); 1S.e5{
//if(nThreadID == 1) dK(%u9v
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U.j\u>a
} V1b_z
*Wo$$T
41Q
Utility.log("Thread " + nThreadID + " is over!"); a:%5.!Vd
bDownOver = true; a4qpnr]0
//nPos = fileAccessI.write (b,0,nRead); WyJfF=<
} Nb9V/2c;V
catch(Exception e){e.printStackTrace ();} 88=FPEU
} Dmv
} C`T5d
=|&"/$+s
f(MHU
//打印回应的头信息 M=abJ4
public void logResponseHead(HttpURLConnection con) l \n:"*To
{ #V,~d&_k
for(int i=1;;i++) f I-"8f0_
{ &EJ,k'7$
String header=con.getHeaderFieldKey(i); ]B'
if(header!=null) WHavz0knf[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1Kf t?g
Utility.log(header+" : "+con.getHeaderField(header)); k<";t
else ^^Q32XC,
break; `ip69 IF2*
} Ywk[VD+.
} MC)W?
R/xCS.yl}
cYn}we}7
public void splitterStop() &r%^wfp
{ ZUI9[A?
bStop = true; V+~2q=
} $=SYssg7La
8/$iCW
dY`J,s
} PCnJ2
DJjDKVO5t
J|8YB3K,
/* :@A;!'zpL
**FileAccess.java ):EXh#
*//文件访问(定位，写) 0nnq/u^
package NetFox; k6XmBBIj-
import java.io.*; -7VV5W
I T2sS6&R
3H%WB|
public class FileAccessI implements Serializable{ %b4(wn?n:B
EPnB%'l\c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SntYi0,`
RandomAccessFile oSavedFile; hd%F7D5
long nPos; 5R G5uH/-<
]>T/Gl1
F4gc_>{|
public FileAccessI() throws IOException hIr^"kVK
{ HjR<4;2
this("",0); Hf|:A(vCx
} l6Bd<tSH
YHAg4eb8
P*sCrGO%
public FileAccessI(String sName,long nPos) throws IOException Rx2|VD
{ "S#hzrEdYI
oSavedFile = new RandomAccessFile(sName,"rw"); 7J/3O[2
this.nPos = nPos; aX:$Q }S
oSavedFile.seek(nPos); "ET"dMxU
} 1Xc%%j
7|Y8^T s
nJC}wh2d#
public synchronized int write(byte[] b,int nStart,int nLen) `rQl{$9IC
{ e0 EJ[bG
int n = -1; 4{E=wg^p
try{ Vtri"G8 aB
oSavedFile.write(b,nStart,nLen); &ayoTE^0,
n = nLen; HrxEC)V6#
} +M:Q!'
catch(IOException e) Pp!W$C:
{ p {3|W<
e.printStackTrace (); dGjvSK<1@
} d?.x./1[qi
ysPW<
\ 3N#%
return n; 4F?1,-X
} K.~U%v}
,5:86'p
In2D32"F
} f[D#QC
^xrR3m*d
duCm+4,.
/* DGnswN%n1
**SiteInfoBean.java xB#E&}Ho
*/ N8TO"`wdbs
package NetFox; }2S \-
0a5P@;"a
19_F\32
public class SiteInfoBean { CgWj9 [
Oc>-jhx?
_1~Sj*
private String sSiteURL; //Site's URL (@Bm2gH
private String sFilePath; //Saved File's Path aum,bm/0J
private String sFileName; //Saved File's Name Hw Is7
private int nSplitter; //Count of Splited Downloading File F 7=-k/k
yY+2;`CH
Velmq'n
public SiteInfoBean() ='FEC-f95
{//nSplitter的缺省值为5 uH#NJoRO
//default value of nSplitter is 5 @N$r'@
this("","","",5); k)J7) L
} {SJLM0=Z
VF-d^AGt
#3S/TBy,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z7v~;JzC#
{ LLE~V~j
sSiteURL= sURL; >h9U~#G=
sFilePath = sPath; ra3WLK
sFileName = sName; d3\8BKp
this.nSplitter = nSpiltter; ;WhB2/5v
x[X.// :
u0,~pJvX
} WXM_H0K
P+/L,u
P/_XDP./U
public String getSSiteURL() dx~Wm1
{ ;?rW`e2
return sSiteURL; %bsdC0xM
} U{x'@/Ld
^~0r+w61
(Cq-8**dY
public void setSSiteURL(String value) #yqcUbJY0R
{ Hq~ 2,#Ue
sSiteURL = value; ovl@[>OB
} >eXNw}_j
B[$e;h*Aw[
m4iR '~L}
public String getSFilePath() h3:,Gbyap
{ ]u:NE'0Xy
return sFilePath; L]VK9qB
} 7+c@pEU]
G$Dg*<
y`N1I
public void setSFilePath(String value) B4b UcYk
{ >8VJ!Kg4
sFilePath = value; (T^aZuuS
} <I>q1m?KN
HG^8&uh]
*D'VW{
public String getSFileName() U!Lws#\X
{ o%dtf5}(,
return sFileName; /i]Gg \)
} $lv g.u
X2{3I\'Ft
^8 z*f&g
public void setSFileName(String value) J:>TV.TP
{ ^a(q7ZfY
sFileName = value; |9g*rO
} ]/a?:24[
ZpZ~[BtQ
K)k!`du!6
public int getNSplitter() V +hV&|=
{ Fm@GU
return nSplitter; `R^)<v*
} A^~\
3"B|w^6'2
A[b'MNsv
public void setNSplitter(int nCount) cO<x:{`
{ rg $71Ir
nSplitter = nCount; )S`A+M K]
} !~RD>N&n
} J3$ihH.
%~eZrG.
#><.zZ
/* fpzTv3D=I
**Utility.java ?6[>HX;
*/ ]\GGC]:\@
package NetFox; {d3r>Ub)7d
<}e<Zf!
2Gj&7A3b
public class Utility { yXkgGY5
ZJx:?*0a
s*VZLKO
public Utility() u!F3Rh8D
{ aC:rrS
UH)A n:9
c~>M7e(
} \Q#F&q0
h[ tOY
//线程睡眠 Y H?>2u
public static void sleep(int nSecond) Im#3sn
{ \Oc3rJ(
try{ +tuC845
Thread.sleep(nSecond); #-@dc
} pa.W-qyu
catch(Exception e) s(zG.7*3n
{ k1]?d7g$w
e.printStackTrace (); x*_c'\F|
} }U8H4B~UtY
} Lrz>00(*4
=LuA[g
//日志 6~}=? sX4
public static void log(String sMsg) h883pe=
{ e#08,wgW
System.err.println(sMsg); &oAuh?kTq
} i8dv|oa
ty(F;M(
{lqnn n3
public static void log(int sMsg) l_$~~z ~
{ T8ZsuKio]
System.err.println(sMsg); ]T+{]t
} ^gNAGQYA
} 7|H !(a'
)82x)c<e
g{dyDN$5|w
/* \<V{6#Q=
**TestMethod.java ]2tX'=X
*/ ,u!c|4
package NetFox; tV%M2DxS
Y]ZOvA5W
fNQ.FAK":
public class TestMethod { taI])
?. CA9!|
1)M3*h3
public TestMethod() ba|~B8rII[
{ ///xx/weblogic60b2_win.exe nz+DPk["
try{ trg+")a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); YS/{q~$t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [O9(sWL'
SiteFileFetch fileFetch = new SiteFileFetch(bean); nB"q
fileFetch.start(); ^-mz!{
} 8!E$0^)c|
catch(Exception e){e.printStackTrace ();} pX|\J>u)
|fq1Mn8
#;>J<>
} m?bb/o'B
Spt[b.4mF
_qM'm^z5
public static void main(String[] args) pn>zuHe
{ $0NWX
new TestMethod(); ,~%Qu~\
} 7DXT1+t
} ^pAqe8u_
点击下载更多相关资料