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)); n?e@):
} o eJC
for(int i=0;i<nEndPos.length-1;i++) Z!RRe]"y
{ `YmI'
nEndPos = nStartPos[i+1]; Q0q)n=i}]
} w] 5U
nEndPos[nEndPos.length-1] = nFileLength; =Mu'+,dT
} 7Ysy\gZ&wp
} }Cmj(k`~
x#F1@r8R
RSPRfYU/
//启动子线程 xU13fl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ttbQergS
for(int i=0;i<nStartPos.length;i++) M~z(a3@[V
{ LF9aw4:>Ou
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PD}SPOA`U3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {GX &)c4
nStartPos,nEndPos,i); (J^Lqh_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B=q)}aWc
fileSplitterFetch.start(); OHtgn
} k{}[>))Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^Z-.[Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fVA=<:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =N*%f%
nEndPos = " + nFileLength); QSn;a 4f
// fileSplitterFetch[nPos.length-1].start(); fbHWBb
V 4\^TO`q=
p;n3`aVh
//等待子线程结束 a_ 9|xI
//int count = 0; 3lLW'g&=
//是否结束while循环 GLaZN4`
boolean breakWhile = false; \~z?PA.$
=2;mxJ#o
I!F}`d
while(!bStop) a9? v\hG
{ \N`fWh8&
write_nPos(); e_I; y
Utility.sleep(500); J3lG"Ww
breakWhile = true; Z0()pT
as\<nPT{Fj
Xc8= 2n
for(int i=0;i<nStartPos.length;i++) [D<RV3x9
{ 0okO+QU,a
if(!fileSplitterFetch.bDownOver) (E"&UC[
{ Gs_*/E7,
breakWhile = false; ]ZR{D7.?
break; Xb(CH#*{z
} ueWR/
} Qfkh0DX B
if(breakWhile) 2A*X Hvwb
break; ~8H&m,{j
!F0rd9
*} *!+C3
//count++; 7gVh!rm
//if(count>4) };|!Lhl+
// siteStop(); MO));M)
} Lf,CxZL5
'L>&ZgLy
Cbgj@4H
System.err.println("文件下载结束！"); F:[7^GQZ{
} ou<S)_|Iu
catch(Exception e){e.printStackTrace ();} N`,7FI}
} 5`4}A%@&
kP!%|&w;
Tm%$J
//获得文件长度 fs2mN1
public long getFileSize() Qa,NGP.
{ itqQ)\W
int nFileLength = -1; 90
try{ s jL*I
URL url = new URL(siteInfoBean.getSSiteURL()); 763E 6,7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NqiB8hZ~
httpConnection.setRequestProperty("User-Agent","NetFox"); w8AJ#9W
wb(*7 &eP:
o|z+!,
int responseCode=httpConnection.getResponseCode(); ^?$D.^g
if(responseCode>=400) c[(yU#@
{ &ui:DZAxj|
processErrorCode(responseCode); b\SXZN)Be
return -2; //-2 represent access is error ?8Hn{3X
} mV6#!_"
Y5nz?a
<MPeh&_3#
String sHeader; _v1bTg"?
u/z,92mmS
Pk$}%;@v
for(int i=1;;i++) ggerh#
{ 2-B6IPeI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $cRcap
//Utility.log(in.readLine()); T&o,I
sHeader=httpConnection.getHeaderFieldKey(i); NzjMk4t
if(sHeader!=null) %)zk..K{l
{ IkSX\*
if(sHeader.equals("Content-Length")) ^36M0h|R
{ oHxGbvQc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^H'hD
break; hmc\|IF`
} Jb(DJ-&
} Zw2jezP@t
else Gh2#-~|cB
break; zx ct(
} A;odVaH7
} v2IEJ
catch(IOException e){e.printStackTrace ();} A ?#]s
catch(Exception e){e.printStackTrace ();} :9(3h"
>NJjS8f5
YkSuwx@5_q
Utility.log(nFileLength); /rqqC(1
xC<R:"Mn
wHA/b.jH
return nFileLength; ,oBlJvm
} #]@9qPyn
b2G2cL-(
Q6u{@$(/N
//保存下载信息（文件指针位置） xM% pvx.'L
private void write_nPos() I"B8_
{ g8KY`MBnC&
try{ ,g%o
output = new DataOutputStream(new FileOutputStream(tmpFile)); w-r_H!-
output.writeInt(nStartPos.length); Ft3I>=f{
for(int i=0;i<nStartPos.length;i++) y7>iz6N
{ !IN@i:m
// output.writeLong(nPos); 9t#P~>:jY}
output.writeLong(fileSplitterFetch.nStartPos); yDzdE;
output.writeLong(fileSplitterFetch.nEndPos); hXNH"0VCV
} vuXS/ d
output.close(); HF]EU!OT
} p7s@%scp
catch(IOException e){e.printStackTrace ();} >o#ERNf
catch(Exception e){e.printStackTrace ();} h(_P9E[g
} \WcB9
,`yyR:F
4b]_ #7Qm
//读取保存的下载信息（文件指针位置） Yhe+u\vGs\
private void read_nPos() F#B5sLNb
{ sA3UeTf
try{ z*RSMfRW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >jv\Qh
int nCount = input.readInt(); $.wA?`1aSk
nStartPos = new long[nCount]; p+RAtRf
nEndPos = new long[nCount]; >'N!dM.+9
for(int i=0;i<nStartPos.length;i++) _$8{;1$T?
{ 8qN"3 Et
nStartPos = input.readLong(); V>B'+b+<
nEndPos = input.readLong(); m*`cuSU|o
} 4\\.n
input.close(); i=-8@
} WK*S4c
catch(IOException e){e.printStackTrace ();} R+d< fe
catch(Exception e){e.printStackTrace ();} w(Gz({l+
} kymn)Ea
'[Xl>Z[
0potz]}
private void processErrorCode(int nErrorCode) \04mLIJr9
{ |gW
System.err.println("Error Code : " + nErrorCode); (|dPeix|
} Qo.Uqz.C
vGMJ^q
_PV*lK=
//停止文件下载 mW~P!7]
public void siteStop() t-!m vx9Z
{ pr$~8e=c
bStop = true; D;jK/2
for(int i=0;i<nStartPos.length;i++) :&9TW]*g
fileSplitterFetch.splitterStop(); Ge^Qar
@ ICbKg:
0Qp[\ia
} Fom>'g*
} Z["BgEJ
//负责部分文件的抓取 Pr`s0J%m
**FileSplitterFetch.java p-,Iio+
*/ S.W^7Ap
package NetFox; ck$M(^)l
)km7tA 0a
ZjS(ad*.2
import java.io.*; /=TH08
import java.net.*; XMw.wQ'?
'#W_boN
W^k,Pmopy
public class FileSplitterFetch extends Thread { iV!@bC,
vr4O8#
;%WdvnW
String sURL; //File URL .TJ">?
long nStartPos; //File Snippet Start Position ) "[HZ/
long nEndPos; //File Snippet End Position T9?54r
int nThreadID; //Thread's ID ;%Q&hwj
boolean bDownOver = false; //Downing is over x,\!DLq:p
boolean bStop = false; //Stop identical R*bmu
FileAccessI fileAccessI = null; //File Access interface B)6#Lp3
NI.`mc6Xd
{fU?idY)c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qp&4 1
{ `|EH[W&y
this.sURL = sURL; \2>?6zs
this.nStartPos = nStart; nvt$F%+
this.nEndPos = nEnd; h>klTPM>
nThreadID = id; I+",b4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 AkA!:!l
} "r..
OJpj}R
'E-FO_N
public void run() |` "?
{ 2m"_z
while(nStartPos < nEndPos && !bStop) \ha-"Aqze3
{ )7Ixz1I9g
A=X-;N#
)xt4Wk/
try{ EnJ!mr
URL url = new URL(sURL); ^N-'xy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #\ #3r
httpConnection.setRequestProperty("User-Agent","NetFox"); ,r`UBQ}?
String sProperty = "bytes="+nStartPos+"-"; X;VQEDMPU
httpConnection.setRequestProperty("RANGE",sProperty); OH6n^WKY
Utility.log(sProperty); .6m_>Y6
O%g\B8;
[zh"x#AyI
InputStream input = httpConnection.getInputStream(); %w5[*V
//logResponseHead(httpConnection); ,Sg33N?
opD-vDa h
bX2"89{
byte[] b = new byte[1024]; L/i(KF{
int nRead; ARWZ; GX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) * t!r@k
{ 9i%9
nStartPos += fileAccessI.write(b,0,nRead); wf9z"B
//if(nThreadID == 1) +EkW>$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u7].}60.'
} z"UPyW1?
1bSD,;$sQ
,2,5Odrz
Utility.log("Thread " + nThreadID + " is over!"); x=*L-
bDownOver = true; aWGon]2p
//nPos = fileAccessI.write (b,0,nRead); Mu2`ODe]
} OCK>%o$[
catch(Exception e){e.printStackTrace ();} pM2a(\K,k^
} m@\ZHbq
} re`t ]gzb
<3Gqv9Y&
:=fvZAWD
//打印回应的头信息 iM5vrz`n
public void logResponseHead(HttpURLConnection con) 9Cvn6{
{ X+l'bp]Ry
for(int i=1;;i++) :E'P7A
{ O+"ac /r
String header=con.getHeaderFieldKey(i); Vz"u>BP3~
if(header!=null) K)N0,Qwu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %|+E48
Utility.log(header+" : "+con.getHeaderField(header)); @cv{rr
else T)SbHp Y
break; H?Jm'\~
} Z<"K_bj
} > 0.W`j(s
Eju~}:Lo
WG5W0T_
public void splitterStop() fdv`7u+}a
{ BsLG^f
bStop = true; W^3;F1
} 1@_T m
#/ "+
Z cpmquf8L
} /3B6Mtb
1%`7.;!i
BX< dSK
/* AGq>=avv
**FileAccess.java 9wh2f7k
*//文件访问(定位，写) YRcps0Dx9
package NetFox; XG 0v
import java.io.*; VQxpN 1
vAi$[p*im
|d}MxS`^
public class FileAccessI implements Serializable{ _MfD
{{!Y]\2S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fly,-$K>LO
RandomAccessFile oSavedFile; 2R.2D'4)`
long nPos; UVEz;<5@\
J4aBPq`
KQ`=t
public FileAccessI() throws IOException ||eAE)
{ 1*Ar{:+ua
this("",0); `G$1n#&
} BfmsMW
k6**u
;[$n=VX`
public FileAccessI(String sName,long nPos) throws IOException -<f;l_(
{ Q+$Tt7/
oSavedFile = new RandomAccessFile(sName,"rw"); +j[oEI`e
this.nPos = nPos; Z|*!y]We
oSavedFile.seek(nPos); I021p5h|
} #A<P6zJXR
0q6I;$H
Ee2c5C!|C
public synchronized int write(byte[] b,int nStart,int nLen) RBGX_v?
{ v:|(8Y
int n = -1; )qU7`0'8
try{ (@sp/:`6
oSavedFile.write(b,nStart,nLen); R,_d1^|*w
n = nLen; >e&:`2%.
} Y+-xvx :
catch(IOException e) "!UVs+)]
{ ;4#D,zlO^
e.printStackTrace (); LE=k
} [QczlwmO
*"{&FEV
x?yD=Mq_
return n; XbXA+ey6
} 9#/(N#>
N{C;~'M2ce
=o=1"o[
} oC|WBS
\%A%s*1
xN0*8
/* V H^AcO
**SiteInfoBean.java A(d5G^
*/ ktH8as^54!
package NetFox; z2yJ#
M>H=z#C>/A
my.`k'
public class SiteInfoBean { W WG /k17
}_OM$nzj
fI|[Z+"
private String sSiteURL; //Site's URL f4('gl9
private String sFilePath; //Saved File's Path ^U q
private String sFileName; //Saved File's Name 5#JJ?
private int nSplitter; //Count of Splited Downloading File ;/8{N0
[=TCEU{"~
SU%DW46
public SiteInfoBean() UlovXb
{//nSplitter的缺省值为5 G*}F5.>8(
//default value of nSplitter is 5 saZ>?Owz
this("","","",5); yy2I2Bv
} cu7(.
Q(@IK&v
D!LX?_cD1i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?Dsm~bkX[
{ P=8>c'Q
sSiteURL= sURL; F?4(5 K
sFilePath = sPath; kCP$I732
sFileName = sName; jUMf6^^
this.nSplitter = nSpiltter; H{G{H=K_
]B4}eBt5)@
%i0\1hhV<
} @xWdO,#
,"?A2n-qO
w~\%vXla
public String getSSiteURL() h{iEZ#
{ ,/Cq v
return sSiteURL; A.%CAGU5w
} B|{I:[
3:CO{=`\7B
;h/pnmhP
public void setSSiteURL(String value) 2j&@p>
{ >yK0iK{
sSiteURL = value; =tdSq"jh
} m}Y0xV9
`$5UHa2/
sq0 PBEqq
public String getSFilePath() .0y%5wz8j
{ P\R27Jd
return sFilePath; +C{p%`<
} A}VYb:u/
8HErE<_(
Qo0H
public void setSFilePath(String value) r0dDHj~F
{ 6L4$vJ
sFilePath = value; M:SO2Czz
} vA%^`5
\F6LZZ2Lv
j|_E$L A\
public String getSFileName() l}g;'9ZB
{ %Z]'!X
return sFileName; d5j_6X
} h#}YKWL
arZ@3]X%a
,TC;{ $O5
public void setSFileName(String value) x8#ODuH
{ SAv<&
sFileName = value; `k{& /]
} {bNXedZ\
omX?Bl
8\ha@&p
public int getNSplitter() QBJ3iQs1
{ j6}R7$JR
return nSplitter; ZU&"73
} fZWGn6$
90N`CXas
mj,fp2D;%
public void setNSplitter(int nCount) '?*g%Yuz
{ j -O2aL
nSplitter = nCount; KpiF0K
} 9h,u6e
} >`T5]_a
]> !<G8=N
hsLzj\)6
/* )h$NS2B`
**Utility.java Vd9@Dy
*/ <eN R8(P
package NetFox; /\d$/~BFi
UHO_Z
]gb=
public class Utility { S[:xqzyDg
irBDGT~
g^>#^rLU
public Utility() v Y|!
{ GR4?BuY,
H^%.=kf
[THG4582oB
} B7*}c]^6/
Z0,~V
//线程睡眠 d.<~&.-$
public static void sleep(int nSecond) k)(Biz398E
{ UH`hOJ?
try{ ?:rx1}:F
Thread.sleep(nSecond); h rN%
} o@E/r.uK
catch(Exception e) -7-['fX
{ )|#%Czd4
e.printStackTrace (); p#d+>7
} xBnbF[
} Zf*r2t1&P
ZFh+x@
//日志 %i{;r35M;9
public static void log(String sMsg) *e"a0
{ cd@.zg'sYn
System.err.println(sMsg); @]CF&: P A
} jk~:\8M(A
!mfJpJ
dx_6X!=.J
public static void log(int sMsg) Bo_ym36N
{ ZDLMMXx>
System.err.println(sMsg); Bd0eC#UGkQ
} D #2yIec
} zri} h/{
/M0/-pV9
B\`Aojw"E?
/* zzpZ19"`1
**TestMethod.java ^+70<#Xc
*/ " BTE
package NetFox; F 8yF
%oykcf,#
}E<^gAh}
public class TestMethod { P @%.`8
x ,/TXTZ6
Ps[$.h
public TestMethod() eH>#6R1-
{ ///xx/weblogic60b2_win.exe "AueLl)
try{ 6)RbPPeE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &M&{yc*%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A]`:VC=IU
SiteFileFetch fileFetch = new SiteFileFetch(bean); j}HFs0<L
fileFetch.start(); <_S@6?
} |lQ;ALH!
catch(Exception e){e.printStackTrace ();} {kB `>VS
G&{HTYP
| FM }
} M7}Q=q\9
|!z2oO
cL7g}$W$
public static void main(String[] args) <EX7WA
{ |(IO=V4P
new TestMethod(); 0OZMlt%z
} LC69td&
} w:=V@-S8
点击下载更多相关资料