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)); D0y,TF
} 76_8e{zbr
for(int i=0;i<nEndPos.length-1;i++) v(@+6#&
{ xK),:+G(
nEndPos = nStartPos[i+1]; &>zy_)
} b!5tFX;J
nEndPos[nEndPos.length-1] = nFileLength; aEFe!_QY
} v>y8s&/
} :Bv&)RK
? W2I1HEy
8~s-t
//启动子线程 wO_pcNYZ8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i5E:FS^!I
for(int i=0;i<nStartPos.length;i++) ;sck+FP7w
{ Sp`fh7d.(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $-fjrQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |Y8Mk2,s
nStartPos,nEndPos,i); i_9Cc$Qh<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y6f+__O
fileSplitterFetch.start(); cGpN4|*rQ
} qD$GKN.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J]|6l/i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [!:-m61
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Wp7@
nEndPos = " + nFileLength); }/7.+yD
// fileSplitterFetch[nPos.length-1].start(); MgH1d&R
]U#[\ Z
RP`GG+K
//等待子线程结束 @;m@Luk
//int count = 0; m|nL!Wc
//是否结束while循环 -n=$[-w
boolean breakWhile = false; G%j/eTTf
^:cb $9F
=2;mxJ#o
while(!bStop) yd0=h7s
{ 5I)~4.U|,m
write_nPos(); &e HM#as
Utility.sleep(500); ?O<`h~'$+
breakWhile = true; cwM#X;FGq
+ 4V1>e+
nCffBc
for(int i=0;i<nStartPos.length;i++) `Ct'/h{
{ Xc8= 2n
if(!fileSplitterFetch.bDownOver) [D<RV3x9
{ 0okO+QU,a
breakWhile = false; ~{1/*&P
break; (<]\,pP0_
} _XY`UZ
} HsjELbH
if(breakWhile) ]=?X*,'
break; ueWR/
xUiWiOihr6
9:9N)cNvfX
//count++; JAGi""3HG
//if(count>4) ;xW8Z<\-
// siteStop(); gZ`32fB%
} *} *!+C3
BB2_J=wA
w|!YoMk+o
System.err.println("文件下载结束！"); tsTR2+GZS
} Z-^uM`],G
catch(Exception e){e.printStackTrace ();} O3^98n2
} '2Q.~6
{\vI9cni|"
o9KyAP$2
//获得文件长度 olD@W UB
public long getFileSize() l?[{?Luq
{ f pv= P
int nFileLength = -1; JYZ2k=zh
try{ 7>nhIp))
URL url = new URL(siteInfoBean.getSSiteURL()); +8LM~voB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,~?A,9?%:
httpConnection.setRequestProperty("User-Agent","NetFox"); J-t=1
eVqM=%Q
JDC=J(B
int responseCode=httpConnection.getResponseCode(); nwa\Lrh
if(responseCode>=400) ;yk9(wea}"
{ @wd!&%yzO
processErrorCode(responseCode); E/"YId `A
return -2; //-2 represent access is error ~pHJ0g:t
} h|J;6Sm@
2x-'>i_|g
a~8:rW^
String sHeader; aqcFY8b '
??%)|nj.
U>/<6Wd
for(int i=1;;i++) IY];Ss&i
{ bin6i2b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]*bAF^8i
//Utility.log(in.readLine()); XHWh'G9
sHeader=httpConnection.getHeaderFieldKey(i); J|n(dVen/
if(sHeader!=null) 2-B6IPeI
{ 9uA, +
if(sHeader.equals("Content-Length")) Y*5Z)h 1
{ 7ZS>1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); UJ7'JBT=k
break; >}-~rZ
} `)rg|~#k
} |?\gEY-Se
else qru2h #
break; PYdIP\<V
} 5."5IjZu
} U8 Z~Y}29
catch(IOException e){e.printStackTrace ();} ' oBo|
catch(Exception e){e.printStackTrace ();} l'|E,N>X
\BN|?r$a
^H'hD
Utility.log(nFileLength); J9g|#1G
@''&nRC1
w@87]/4Rq
return nFileLength; _aVJ$N.
} /)sDnJ1r
/0Z|+L9Jo
zl0;84:H
//保存下载信息（文件指针位置） t[%x}0FP-F
private void write_nPos() ^Ku\l #B
{ ~RcNZ\2y
try{ VT'0DQ!NIq
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^Y$QR]
output.writeInt(nStartPos.length); {d| |q<.-
for(int i=0;i<nStartPos.length;i++) 7@FDBjq
{ 0Xp nbB~~I
// output.writeLong(nPos); qpoquWZ
output.writeLong(fileSplitterFetch.nStartPos); |a%B|CX
output.writeLong(fileSplitterFetch.nEndPos); tJff+n>
} iwvt%7
output.close(); Vre=%bGw
} dAL0.>|`0
catch(IOException e){e.printStackTrace ();} (RExV?:
catch(Exception e){e.printStackTrace ();} Kl2}o|b
} #>BX/O*D
$+7ci~gs
*U M!(
//读取保存的下载信息（文件指针位置） g8KY`MBnC&
private void read_nPos() 3 sl=>;-
{ K*[9j 0
try{ l(gJLjTH%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kzMa+(fu
int nCount = input.readInt(); FQ U\0<5
nStartPos = new long[nCount]; pG(Fz0b{
nEndPos = new long[nCount]; AU/#b(mI
for(int i=0;i<nStartPos.length;i++) HF]EU!OT
{ =PV/`I_h
nStartPos = input.readLong(); A1Ka(3"
nEndPos = input.readLong(); ,`yyR:F
} FtN}]@F
input.close(); "2%>M
} <3lUV7!
catch(IOException e){e.printStackTrace ();} FW_G\W.
catch(Exception e){e.printStackTrace ();} UkZ\cc}aC/
} h!v/s=8c
R0vww_fz
l^ARW E
private void processErrorCode(int nErrorCode) 4\\.n
{ ?d4Boe0-a2
System.err.println("Error Code : " + nErrorCode); MO-!TZ+6
} lu]o34
`YU=~xQ
%Z7%jma
//停止文件下载 Nl {7
public void siteStop() $6# lTYN~
{ yQ'eu;+]
bStop = true; "?P[9x}
for(int i=0;i<nStartPos.length;i++) vnTq6:f#M
fileSplitterFetch.splitterStop(); ^Z#@3=
.9OFryo
3?@?-q2g
} IO"hF
} c yP,[?N
//负责部分文件的抓取 Sl"BK0:%7
**FileSplitterFetch.java ;T>+,
*/ 0yz~W(tsm
package NetFox; 'PpZ/ry$
+bUW!$G
~p\n&{P0
import java.io.*; >fH*XP>(
import java.net.*; )&,K94
.TJ">?
Ig9d#c
public class FileSplitterFetch extends Thread { NF mc>0-
dMV=jJ%Y
L,$3Yj
String sURL; //File URL q$T8bh,2
long nStartPos; //File Snippet Start Position _f|/*. @Q
long nEndPos; //File Snippet End Position 3fp> 4;ym'
int nThreadID; //Thread's ID +ubnx{VC
boolean bDownOver = false; //Downing is over '_0
boolean bStop = false; //Stop identical 3;l"=#5
FileAccessI fileAccessI = null; //File Access interface 5kn+ >{jh`
,Kw5Ro`I:
:6D0j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException TBnvV 5_
{ aMJ;bQD
this.sURL = sURL; kiX%3(
this.nStartPos = nStart; .$0Pr%0pWI
this.nEndPos = nEnd; $;`I,k$0>~
nThreadID = id; 62\&RRB i
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E FY@Y[
} ST;t, D:
A5nO=
H l<$a"K7\
public void run() [BDGR B7d"
{ v}[dnG
while(nStartPos < nEndPos && !bStop) "b,%8
{ z$[C#5+2
Jpj!rXTX*
!')y&7a~
try{ ;t(f1rPyE
URL url = new URL(sURL); Zyye%Ly
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e@n!x}t8
httpConnection.setRequestProperty("User-Agent","NetFox"); MGt]'}
String sProperty = "bytes="+nStartPos+"-"; J|~26lG
httpConnection.setRequestProperty("RANGE",sProperty); gEJi[E@
Utility.log(sProperty); BfmsMW
uk7'K 0j
tIuoD+AW
InputStream input = httpConnection.getInputStream(); EKZVF`L
//logResponseHead(httpConnection); la^ DjHA$
PQ U]l"A
%2l7Hmp4H
byte[] b = new byte[1024]; *xs!5|n+
int nRead; HY}j!X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Fn|gVR
{ Lm%GR[tyQ
nStartPos += fileAccessI.write(b,0,nRead); Y+-xvx :
//if(nThreadID == 1) "!UVs+)]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P?ep]
} y,Q5;$w8
P0GeZ02]
<7sIm^N
Utility.log("Thread " + nThreadID + " is over!"); uCP>y6I
bDownOver = true; 7Z,/g|s}z
//nPos = fileAccessI.write (b,0,nRead); 7^:4A'
} }1H=wg>\
catch(Exception e){e.printStackTrace ();} Oejq@iM"(
} Z)"61) )
} EeQ5vqU
h{iEZ#
w YNloU
//打印回应的头信息 w!3>N"em
public void logResponseHead(HttpURLConnection con) 4sFv?W
{ Qvoqx>2p5
for(int i=1;;i++) 5z/Er".P
{ oduDA:
String header=con.getHeaderFieldKey(i); DPDe>3Mi[
if(header!=null) &eZfQ27$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L2z2}U=<
Utility.log(header+" : "+con.getHeaderField(header)); /!xF?OmVd
else v> z@
break; ,TC;{ $O5
} v:_B kHN'
} `k{& /]
6tjcAsV
|QZ58)>
public void splitterStop() j) vlM+
{ yubSj*
bStop = true; h5zVGr
} %"$@%"8;3
F@<0s&)1
T=Z.U$
} >`T5]_a
U yqXMbw@
deX5yrvOie
/* A7XnHPIw
**FileAccess.java <eN R8(P
*//文件访问(定位，写) JqUADm
package NetFox; !^fa.I'mM
import java.io.*; $ItF])Bj5N
vP-M,4c
t2{~bzq1X
public class FileAccessI implements Serializable{ Z'v-F^
]rBM5~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v6a]1B
RandomAccessFile oSavedFile; ^(x^6d
long nPos; Bstk{&ew
x2VBm$>
WgR4Ix^L#
public FileAccessI() throws IOException }odV_WT
{ ,t$,idcT+
this("",0); kUHE\L.Y]
} Zf*r2t1&P
ZFh+x@
%i{;r35M;9
public FileAccessI(String sName,long nPos) throws IOException *e"a0
{ cd@.zg'sYn
oSavedFile = new RandomAccessFile(sName,"rw"); 8%{q%+
this.nPos = nPos; !UBO_X%dz
oSavedFile.seek(nPos); B)SLG]72f
} vFmJ;J
vxlOh.a|/L
wzcai 0y*
public synchronized int write(byte[] b,int nStart,int nLen) USML~]G z
{ #TJk-1XM*q
int n = -1; m@xi0t
try{ oUDVy_k
oSavedFile.write(b,nStart,nLen); |VH!)vD
n = nLen; !|wzf+V
} eOlKbJU
catch(IOException e) |?m` xO
{ tV;%J4E'
e.printStackTrace (); HaNboYW_K
} wNCCH55Pt
/ci]}`'ws
,%"xH4d
return n; h+UnZfm
} ,8Iv9M}2
m 40m<@
JHV)ZOO
} &M&{yc*%
A]`:VC=IU
<_S@6?
/* QOFvsJ<s
**SiteInfoBean.java H:&?ha,9
*/ >O`l8tM
package NetFox; eBW=^B"y+
Jcf"#u-Q/
P8yIegPY
public class SiteInfoBean { 8}p8r|d!ls
<EX7WA
|(IO=V4P
private String sSiteURL; //Site's URL 0OZMlt%z
private String sFilePath; //Saved File's Path LC69td&
private String sFileName; //Saved File's Name w:=V@-S8
private int nSplitter; //Count of Splited Downloading File (-yl|NFBw
T`YwJ6N
|WQ9a' '
public SiteInfoBean() gvavs+H%
{//nSplitter的缺省值为5 cA`4:gp
//default value of nSplitter is 5 ~4#B'Gy[
this("","","",5); Wsz0yHD[`
} &k>aP0k"
`$;+g ,
@uleyB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3x*z\VJ
{ 0~A#>R'
sSiteURL= sURL; eb:A1f4L
sFilePath = sPath; u</8w&!
sFileName = sName; I+?hG6NM
this.nSplitter = nSpiltter; rs8\)\z
B&KL2&Z~Pq
{ShgJ;! Q
} mB55PYA
3Kq`<B~%
\{|ImCH
public String getSSiteURL() x-m/SI]_N
{ 9M$/=>^ Z
return sSiteURL; ?Hz2-Cn
} c$M%G)P
/Bv#) -5
y.a]r7
public void setSSiteURL(String value) 5N/Lk>p1u
{ I*)VZW
sSiteURL = value; >9K//co"of
} n]? WCG}cd
0&w0aP`Y
}p3b#fAr
public String getSFilePath() j BS4vvX?
{ .(Y6$[#@
return sFilePath; XX;6 P
} Opg#*w%-
[=M%
|7F*MP
public void setSFilePath(String value) K'b*A$5o
{ L4'[XcY
sFilePath = value; wz(K*FP
} 440FhDMj
pWaPC/,g
/p`&;/V|
public String getSFileName() 5D`26dB2
{ f05d ;
return sFileName; zmFws-+A
} ~9M!)\~
;IP~Tb]&
D!3{gV#
public void setSFileName(String value) v548ysE)
{ 5G*II_j
sFileName = value; R 1zC.m
} p8>%Mflf
&r_uQbx
TUTe9;)
public int getNSplitter() |r=DBd3
{ )2j:z#'>
return nSplitter; bKz{wm%
} 3VO:+mT
\HSicV#i
?Myh7
public void setNSplitter(int nCount) O.\h'3C
{ 7sV/_3H+
nSplitter = nCount; uH{'gd,q8
} 5w3Fqu>39?
} 78Y@OL_$
h8v>zNf'
rG6\ynBX%
/* X0i3_RVa
**Utility.java h}Ygb-uZ
*/ mnQ'X-q3iO
package NetFox; 4F#%f#"
`iYc<N`
:t$A8+A+0
public class Utility { {8CWWfHCD
&=w|vB)(p
UzQ$B>f
public Utility() avNLV
{ aqL<v94wX
$Z6D:"K
f%Ke8'&
} UxqWnHH.`
Q1V2pP+=@
//线程睡眠 /~hbOs/ L
public static void sleep(int nSecond) 2VYvO=KA
{ UKs$W`
try{ g [L
Thread.sleep(nSecond); htHv&
} azGnP3_
catch(Exception e) @PXXt#
{ y^s1t2]%
e.printStackTrace (); n2'|.y}Um:
} P;GprJ`l
} qx%jAs+~
n7iE8SK|k
//日志 $ I<|-]u
public static void log(String sMsg) l>Av5g)
{ h$&rE@N|
System.err.println(sMsg); Czu1)y
} DTy/jaK
,cQA*;6
n-OWwev)
public static void log(int sMsg) e^frVEV
{ 6\`DlUn'*
System.err.println(sMsg); r$DZkMue
} 9[{sEg=C$e
} yWuIu>VJ
U.Hdbmix
B\zoJg&7(
/* 04\Ta
**TestMethod.java 2IzfP;V?
*/ ]Zv,
package NetFox; 'A1E^rl]=
GZ,j?@
m9I(TOw
public class TestMethod { )BpIxWd?
e sGlMq
2D_6
public TestMethod() ULck
{ ///xx/weblogic60b2_win.exe QU%N*bFW%P
try{ ]3 j[3'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #4lHaFq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8nf4Jk8r
SiteFileFetch fileFetch = new SiteFileFetch(bean); kp.|gzA6
fileFetch.start(); Es:5yX!
} ec#_olG%
catch(Exception e){e.printStackTrace ();} e00RT1L
uiuTv)pwF
VAt>ji7c
} QdirE4W
~{9x6<g!
R rxRa[{Z
public static void main(String[] args) zQ=aey%
{ 2-PI JO
new TestMethod(); Od*v5qT;$
} 83B\+]{hD
} A?\h|u<
点击下载更多相关资料