http断点续传简单实现（java)

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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)); -o<L%Y<n2
} M7&u_Cn?
for(int i=0;i<nEndPos.length-1;i++) Ml` f+$
{ h_ef@ZwSw
nEndPos = nStartPos[i+1]; iha{(-
} 0[@9f1Nk4
nEndPos[nEndPos.length-1] = nFileLength; RwMK%^b
} ps1ndGp~#
} $}0q=Lg%wv
D;.O#bS
"Zd4e2>{M\
//启动子线程 OJng
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &K5wCNX1
for(int i=0;i<nStartPos.length;i++) %-!ruc"}
{ (3`Q`o;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5;5;bBo~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7q*L-Xe]k
nStartPos,nEndPos,i); vdrV)^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qt5CoxeJ
fileSplitterFetch.start(); ,Ju f
} :9N~wd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EotZ$O=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "/Fp_g6#:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", sXp>4MomV
nEndPos = " + nFileLength); =s`\W7/;{-
// fileSplitterFetch[nPos.length-1].start(); WJBi#(SY
ZzPlIl}\
dxbP'2~
//等待子线程结束 ~TCz1UWV
//int count = 0; f^il|Obzl
//是否结束while循环 tL(B gku9
boolean breakWhile = false; I#QBJ#
<@xp. Y
O1IR+"0
while(!bStop) vt}+d StUm
{ tbD>A6&VM}
write_nPos(); sh(G{Yz@
Utility.sleep(500); X=)Ue
breakWhile = true; 2C^/;z
tjc3;9
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for(int i=0;i<nStartPos.length;i++) mxsmW
{ e`ti*1]q
if(!fileSplitterFetch.bDownOver) v 0mc1g+9
{ z/u;afB9q
breakWhile = false; |r5 np
break; AFO g*{1
} $6.CN#
} <RY5ZP
if(breakWhile) =jIB5".
break; eeb`Ao
FOiwB^$>
1 zIFQ@
//count++; ;n_|t/=
//if(count>4) )$K )`uqb
// siteStop(); aOWW..|
} y?j#;n0
|D<J9+
3jQy"9f
System.err.println("文件下载结束！"); hN*,]Z{
} %Cbqi.iuQ
catch(Exception e){e.printStackTrace ();} gw_]Y^U
} f2]O5rXp
wqE+hKs,
"eH.<&
//获得文件长度 \sc's7
public long getFileSize() caD|*.b
{ Z~6PrM-M
int nFileLength = -1; \wb0%> 0
try{ 4iC=+YUn
URL url = new URL(siteInfoBean.getSSiteURL()); UC*\3:>'n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cz.,QIt_
httpConnection.setRequestProperty("User-Agent","NetFox"); %$ ^eY'-'
Bxf]Lu,\U@
RA ER\9i
int responseCode=httpConnection.getResponseCode(); \ ~uY);
if(responseCode>=400) C|g]Y 7
{ Z_WJgH2c
processErrorCode(responseCode); k3VRa|Y")
return -2; //-2 represent access is error %(d0`9
} 17) `CM$<[
){FXonVP
ZB'ms[
String sHeader; )D8V;g(7F
bU{lV<R,
BW5!@D2
for(int i=1;;i++) Tq,xW
{ 8iXt8XY3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); up )JU [
//Utility.log(in.readLine()); `\M}~
sHeader=httpConnection.getHeaderFieldKey(i); r NT>{
if(sHeader!=null) T@gm0igW/;
{ t(r}jU=qw
if(sHeader.equals("Content-Length")) 353*D%8
{ ?7cT$/4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .NRSBk
break; [`_-;/Gx2
} $I4:g.gKpG
} i564<1`x
else &A)u!l Ue
break; ]v|n'D-?
} OiJz?G:m
} -;W`0k^
catch(IOException e){e.printStackTrace ();} S0jYk(
catch(Exception e){e.printStackTrace ();} BaXf=RsZ
6sz:rv}
Y9ipy_@_?
Utility.log(nFileLength); B4{clI_i
L)-1( e<x
mm9xO%
return nFileLength; Fz1K*xx'
} XTS%:S
4#Id0['
#@8JYzMq%
//保存下载信息（文件指针位置） {L.=)zt>
private void write_nPos() &KPJB"0L
{ 6o=Q;Mezl
try{ ^rssZQKY[
output = new DataOutputStream(new FileOutputStream(tmpFile)); rls\3R(jt
output.writeInt(nStartPos.length); 4elA<<
for(int i=0;i<nStartPos.length;i++) U_61y;Q"
{ < +X,oxg
// output.writeLong(nPos); :WHbwu,L$
output.writeLong(fileSplitterFetch.nStartPos); >A ?{cbJ
output.writeLong(fileSplitterFetch.nEndPos); K3-Cuku
} {/}p"(^
output.close(); <MzXTy3\
} a1 .+L
catch(IOException e){e.printStackTrace ();} &)GlLpaT
catch(Exception e){e.printStackTrace ();} qJq!0F
} ]7J*(,sp
|)+45e
)| 0(#R
//读取保存的下载信息（文件指针位置） ewVks>lbz
private void read_nPos() k293wS
{ (Z?g^kjq)
try{ tqzr+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g-DFcwO,V
int nCount = input.readInt(); w<Ot0&&
nStartPos = new long[nCount]; I;+>@Cn(g<
nEndPos = new long[nCount]; y@9ifFr
for(int i=0;i<nStartPos.length;i++) + ;_0:+//
{ k`NXYf:
nStartPos = input.readLong(); _`+2e-
nEndPos = input.readLong(); >N-l2?rE
} ]^I[SG,
input.close(); 36\_Y?zx%
} PYr'1D'
catch(IOException e){e.printStackTrace ();} gzEcdDD
catch(Exception e){e.printStackTrace ();} ]BaK8mPl
} wkKSL
]:svR@E
T l8`3`e
private void processErrorCode(int nErrorCode) iJS7g
{ $8`"
System.err.println("Error Code : " + nErrorCode); KO[,C[;|j
} Xo3@-D_c!c
V#X<Yt
qO[_8's8
//停止文件下载 ;Q0H7)t:
public void siteStop() ^9 ^DA!'
{ ~L:H]_8F l
bStop = true; /6:qmh2
for(int i=0;i<nStartPos.length;i++) RO[6PlrRN
fileSplitterFetch.splitterStop(); !Y10UmMu
#wp~lW9!s9
h}Lrpr2r
} f([d/
} }#6~/ W
//负责部分文件的抓取 {xf00/
**FileSplitterFetch.java Bo8NY!
*/ >Q:h0b_$U
package NetFox; R#ZO<g%'
vURgR
i5SDy(?r
import java.io.*; DB(!*6#?
import java.net.*; }^2'@y!(
%e(DPX
$hy0U_}6
public class FileSplitterFetch extends Thread { "(Nt9K%P)
d<[L^s9
\-8aTF
String sURL; //File URL t\-|J SZ
long nStartPos; //File Snippet Start Position a|z@5r%
long nEndPos; //File Snippet End Position J3$@: S'
int nThreadID; //Thread's ID yB|1?L#
boolean bDownOver = false; //Downing is over Y]DC; ,
boolean bStop = false; //Stop identical klnk{R.>|
FileAccessI fileAccessI = null; //File Access interface -_= m j
Ey%KbvNv
e-#Vs{?|r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g}pD%
{ D4sp+
this.sURL = sURL; @@cc/S
this.nStartPos = nStart; ^U##9KkP
this.nEndPos = nEnd; t9)S^: 0
nThreadID = id; yW&ka3j\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @M"( r"ab
} M0$E_*
i8S=uJ]n
5v^tPGg4
public void run() =_CH$F!U
{ / }*}r
while(nStartPos < nEndPos && !bStop) d.HcO^
{ =}YX I
MjWxfW/
uW2 q\
try{ qae|?z
URL url = new URL(sURL); d{"@<0i?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G}g;<,g~
httpConnection.setRequestProperty("User-Agent","NetFox"); )9_W"'V
String sProperty = "bytes="+nStartPos+"-"; 7@\.()
httpConnection.setRequestProperty("RANGE",sProperty); [`b,SX x
Utility.log(sProperty); bs?\ )R5/
\}v@!PQl
cZ|*Zpk
InputStream input = httpConnection.getInputStream(); 4KtD k
//logResponseHead(httpConnection); jVd`J
k>mXh{(
-Pp{aFe
byte[] b = new byte[1024]; Zf3(! a[
int nRead; hmo4H3g!N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U&1O
{ py:L-5
nStartPos += fileAccessI.write(b,0,nRead); 5g-1pzP9
//if(nThreadID == 1) h#UPU7;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \\R<HuTY
} ck `td%
j07A>G-=
a+v.(mCG
Utility.log("Thread " + nThreadID + " is over!"); 6bj77CoB
bDownOver = true; Dj=$Q44
//nPos = fileAccessI.write (b,0,nRead); #s\yO~F-
} ? }ff O
catch(Exception e){e.printStackTrace ();} 9 AD*
} /<T{g0s
} w8q 2f-K-
eVMnI yr
$HOe){G
//打印回应的头信息 GBS+ 4xL|
public void logResponseHead(HttpURLConnection con) PyI"B96gz
{ au=@]n#<(
for(int i=1;;i++) X*7VDt=
{ tIV9Y=ckr0
String header=con.getHeaderFieldKey(i); |ul{d|
if(header!=null) &QQ6F>'T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UnVa`@P^:G
Utility.log(header+" : "+con.getHeaderField(header)); 7ieAd/:_
else Ed0}$b
break; d7X7_
} j)ln"u0R^B
} @>ys,dy
LrdED[Z
,qB@agjvo<
public void splitterStop() ?)<zzL",
{ %'. x vC
bStop = true; ,bM):
} q3v5gz^t
\AI-x$5R*
Ke#Rkt
} M;AvOk|&
XLYGhM
M'X,7hZ
/* <f)T*E^5%
**FileAccess.java CO,{/
*//文件访问(定位，写) @Wm:Rz
package NetFox; +o,f:Ih
import java.io.*; yZoJD{'?Sw
5mL4Zq"
w4Hq|N1-Y
public class FileAccessI implements Serializable{ kbH@h2Ww
l LBzY`j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LV$Ko_9eA
RandomAccessFile oSavedFile; 5TeGdfu @
long nPos; 5K&A2zC|
g&.OJ
IY!8j$'|
public FileAccessI() throws IOException >@a7Zzl0H
{ V+U89j1g
this("",0); -I*vl
} I^n,v) 8
K0I.3|6C
~(Q#G"t
public FileAccessI(String sName,long nPos) throws IOException )@tHS-Jf
{ qrZ3`@C4k
oSavedFile = new RandomAccessFile(sName,"rw"); Cd6th F)
this.nPos = nPos; b8%TwYp
oSavedFile.seek(nPos); m' |wlI[lq
} :7Uv)@iUk
4OAR["f
@1bl<27
public synchronized int write(byte[] b,int nStart,int nLen) "So"oT1
{ ~GJ;;v1b2
int n = -1; f?16%Rk<
try{ u35"oLV6}#
oSavedFile.write(b,nStart,nLen); nC?Lz1re
n = nLen; i;Kax4k
} BbL]0i
catch(IOException e) /m^G 99N
{ E1w8d4P,G
e.printStackTrace (); ,S`FxJcE
} tt6GtYrC 1
g"c7$
i]@k'2N
return n; @W==)S%O
} /+ais3
Oc.8d<
p"H/N_b4
} cBOt=vg,5
(4C)] RHQ
!\Cu J5U
/* hl)jE 06
**SiteInfoBean.java 4L97UhLL
*/ {%&04yq+
package NetFox; O@dK^o
zF? 6"
~6QV?j
public class SiteInfoBean { <F-IF7>a
,[dvs&-*
j+gh*\:q
private String sSiteURL; //Site's URL 7xWJw
private String sFilePath; //Saved File's Path 7*WO9R/
private String sFileName; //Saved File's Name O9ro{ k
private int nSplitter; //Count of Splited Downloading File vD/l`Ib:
#~qzaETv,
uFlf#t =
public SiteInfoBean() wM-H5\9n
{//nSplitter的缺省值为5 1L?W+zMO
//default value of nSplitter is 5 P"@^BQ4
this("","","",5); K_.|FEV
} LFYSur8
FBzsM7]j
VOg'_#I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zx+}>(U\U
{ [`bK {Dq2
sSiteURL= sURL; 2<'ol65/c
sFilePath = sPath; 4((p?jbC
sFileName = sName; bhsCeH
this.nSplitter = nSpiltter; txX>zR*)
?UeV5<TewS
mGF)Ot R
} wCj)@3F
WK#%G
IfI:|w}:"r
public String getSSiteURL() =k1sF3.V'c
{ K]dR%j
return sSiteURL; 6J$I8b#/
} Vk[M .=J
]<Q&
wMCgLh\wi
public void setSSiteURL(String value) @s,kx.S
{ KhL%ov
sSiteURL = value; =xSf-\F
} (FGHt/!
taO(\FOm
+u&3pK>f
public String getSFilePath() <HpUP!q8v
{ hVd_1|/X
return sFilePath; u6MU @?
} )?6%d
7$IR^
8~Pdr]5
public void setSFilePath(String value) w2lO[o~x}
{ z('t#J!b
sFilePath = value; HoeW6UV
} E7/i_Xkk
X7tBpyi
Q=#FvsF#z3
public String getSFileName() )YwLj&e4tf
{ .%M80X{5~
return sFileName; 9}a&:QTHR
} ]bstkf}~u
@V^5_K
e:T9f('
public void setSFileName(String value) f*p=j(sF
{ [N"=rY4G
sFileName = value; N]\)Ok
} Wq}W )E
Ev3,p`zS._
lW4 6S
public int getNSplitter() F9A5}/\
{ l?Ls=J*
return nSplitter; bPV;"
} jI<_(T
4sC)hAx&f
tOo\s&j
public void setNSplitter(int nCount) \+x#aN\
{ = U[$i"+
nSplitter = nCount; -MORd{GF
} Dr"PS >.
} x&$8;2&.
%/SHB
g!z &lQnZ
/* _:Jma
**Utility.java m';4`Y5-
*/ l7Wdbx5x0
package NetFox; 1KjzKFnb
G'wyH[ d/
sHOBT,B
public class Utility { "Id1H
4E$d"D5]>p
6LqF*$+$`
public Utility() JZJb&q){
{ s%A?B8,
KHM,lj*
*q@3yB}
} /4upw`35]
at\$ IK_
//线程睡眠 Oe;1f#`5
public static void sleep(int nSecond) V}FH5z |
{ #E#@6ZomT
try{ 6p.y/LMO
Thread.sleep(nSecond); ViUx^e\
} a|k*A&5u2
catch(Exception e) JZE<oQ_Jm
{ )r(e\_n
e.printStackTrace (); /2 qxJvZ
} =>O{hT^F
} Ml)<4@
n} ]gAX
//日志 &M=15 uCK
public static void log(String sMsg) a;&0u>
{ >;}(?+|f
System.err.println(sMsg); '"h}l`
} m&[(xVM
K1o&(;l8G
Ix0#eoj
public static void log(int sMsg) [I[*?9}$"
{ ^__P;Gr`
System.err.println(sMsg); R?J8#JPXD
} {#&D=7LP
} 9QeBz`lm)
,ruL7|T&
3Y}X7-|)Z
/* J|z>5Z
**TestMethod.java qd7 86~
*/ X_0Ta_u?T
package NetFox; e(NpX_8
V!Q1o!J
9Xv>FVG!
public class TestMethod { Jt3]'Nr04@
85Hb~|0
@+3@Z?!SZ
public TestMethod() ,%FBELqOW
{ ///xx/weblogic60b2_win.exe ]^63n/Twj
try{ c8'!>#$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D6KYkN(,v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =h4* ^NJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); BWbM$@'x
fileFetch.start(); )aOPR|+
} b@yGa%Gz@
catch(Exception e){e.printStackTrace ();} MU; L7^
'7!b#if
8p?Fql}F[
} |G5Me
p)$DpNL% p
yX:*TK4
public static void main(String[] args) YmS}*>oz
{ J1?)z+t9~
new TestMethod(); W+&w'~M
} q@i,$R
} d8|bO#a%9
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