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)); qx3@]9
} w0n.Y-v4i
for(int i=0;i<nEndPos.length-1;i++) b,]QfC
{ ;eYm+e^?.
nEndPos = nStartPos[i+1]; 29R_?HBH
} V gLnpPOQ
nEndPos[nEndPos.length-1] = nFileLength; 92|\`\LP%
} m22FOjk\
} FsI51@V72Q
E<u6 js,
I^h^QeBis
//启动子线程 Gh3b*O_,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d>j`|(\
for(int i=0;i<nStartPos.length;i++) :q_(=EA
{ sTx23RJ9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R"NR-iU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), J[6`$$l0
nStartPos,nEndPos,i); Ke0j8|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :77dl/d%
fileSplitterFetch.start(); ]"Y? ZS;H
} G:'hT=8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xVOoYr>O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fUy:TCS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SJ(<u2J]
nEndPos = " + nFileLength); |X:"AH"S
// fileSplitterFetch[nPos.length-1].start(); X wvH
eEvE3=,hg
y\M]\^[7
//等待子线程结束 p*F.WxB)4
//int count = 0; DEj6 ky
//是否结束while循环 @LQe[`
boolean breakWhile = false; 8G&'ED_&
nksx|i l
{OA2';3
while(!bStop) .xnJT2uu'
{ ]3B8D<p
write_nPos(); L\1&$|?
Utility.sleep(500); u-yVc*<,
breakWhile = true; R(jp
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hfUN~89;
for(int i=0;i<nStartPos.length;i++) 5Oh>rK(
{ Uy$1X
if(!fileSplitterFetch.bDownOver) MM_c{gFF
{ [wHGt?R
breakWhile = false; -\ {.]KL
break; v(5zSo
} 5Q$6~\
} WX@a2c.'
if(breakWhile) pP JhF8Dt
break; *^|.bBG
ozF173iI
Qq,w6ekr
//count++; kkvG=
//if(count>4) W|NT*g{;M
// siteStop(); a!iG;:K
} ){~]-VK
?]1_ 2\M
(e,5 b
System.err.println("文件下载结束！"); a#Yo^"*1
} 1?6zsA%N
catch(Exception e){e.printStackTrace ();} o5k7$0:t/
} hq.XO=0"k
M$@Donx
o*\Fj}l-
//获得文件长度 YzasT:EZN
public long getFileSize() zh{:zT)(1
{ NT3Ti ?J,
int nFileLength = -1; %3ieR}:/e&
try{ s48 { R4
URL url = new URL(siteInfoBean.getSSiteURL()); H_ecb;|mP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ix.I)
httpConnection.setRequestProperty("User-Agent","NetFox"); [^rMM1^,OB
(P=q&]l[
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int responseCode=httpConnection.getResponseCode(); j,:vK
if(responseCode>=400) ,\2w+L5TD
{ J 'qhY'te
processErrorCode(responseCode); o3=2`BvJ
return -2; //-2 represent access is error }iOFB&)w
} 3rRN~$
+;@p'af!9
f9ziSD#
String sHeader; P LHiQ:
KG8:F].u(
ONc-jU^
for(int i=1;;i++) OE{PP9eh
{ "$@Wy,yp
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); kimqm
//Utility.log(in.readLine()); R:[IH2F s
sHeader=httpConnection.getHeaderFieldKey(i); LBCat=d<
if(sHeader!=null) @'D ,T^I
{ ZKk*2EK]2z
if(sHeader.equals("Content-Length")) /8$*{ay
{ 948lL&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n#\ t_/\
break; ,p3moD 3
} szZ8-Y
} 1I^uq>r
else Pr>Pxsr&
break; B'@a36
} *F_ dP
} q-k~L\Ys
catch(IOException e){e.printStackTrace ();} X{-@3tG<r
catch(Exception e){e.printStackTrace ();} 4fuKpLA
[UW%(N
AJ%x"
Utility.log(nFileLength); E <O:
IegZ)&_n
+DpiX&^h
return nFileLength; 7K.in3M(
} !+F6Bf
0P%,1M3d
_7k6hVQ
//保存下载信息（文件指针位置） 0Na/3cz|zg
private void write_nPos() -nsI5\]
{ 8`$lsD
try{ [WAnII
output = new DataOutputStream(new FileOutputStream(tmpFile)); jf|5}5kSlf
output.writeInt(nStartPos.length); r/G6O
for(int i=0;i<nStartPos.length;i++) qRX:eo
{ KcW]"K>p!
// output.writeLong(nPos); r6x"D3
output.writeLong(fileSplitterFetch.nStartPos); Gs0x;91
output.writeLong(fileSplitterFetch.nEndPos); 'IykIf
} q|EE em
output.close(); /&T"w,D
} ophQdJM
catch(IOException e){e.printStackTrace ();} gPA), NrN
catch(Exception e){e.printStackTrace ();} Gv$}>YJ
} :SUU)jLq
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)]W|i9
//读取保存的下载信息（文件指针位置） s .xJ},E9
private void read_nPos() L<`p;?
{ ;OTd<
try{ piy_9nk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;FI"N@z
int nCount = input.readInt(); +OTNn@!9
nStartPos = new long[nCount]; #xlT,:_:)
nEndPos = new long[nCount]; BY&+fKae
for(int i=0;i<nStartPos.length;i++) Kx@Papn|6
{ w4"4(SR.
nStartPos = input.readLong(); /HiRbwQK#
nEndPos = input.readLong(); 3r]m8Hp
} GK>.R<[
input.close(); > ]()#z
} EAE\'9T&g
catch(IOException e){e.printStackTrace ();} REaU=-m-
catch(Exception e){e.printStackTrace ();} ~\C.Nm
} Js'#=
g6wL\g{29
55<f
private void processErrorCode(int nErrorCode) eX1<zzd
{ Px$4.b[{_Y
System.err.println("Error Code : " + nErrorCode); fzhCV
} ZB|y
"F.0(<4)
YR\pt8(z?
//停止文件下载 DNu^4#r
public void siteStop() `1Cg)\&[e0
{ yM}Wg~:D:
bStop = true; /3>5ex>PN
for(int i=0;i<nStartPos.length;i++) ]'%Z&1 w
fileSplitterFetch.splitterStop(); b-Q%cxJ
/xu#ZZ?8F_
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} (n>gC
} F6vN{FI
//负责部分文件的抓取 #*"5F*
**FileSplitterFetch.java z;F6:aBa
*/ *$4EXwt'
package NetFox; k|-P&g
"PI]k
vp#AD9h1
import java.io.*; Fhr5)Z
import java.net.*; SCUsDr+.
:hA=(iz
oU`J~6.&S
public class FileSplitterFetch extends Thread { l^ Q-KUI
o(w xu)
ap7ZT7KW
String sURL; //File URL a'U}.w}
long nStartPos; //File Snippet Start Position ,$xV&w8f\"
long nEndPos; //File Snippet End Position )T_o!/\*|*
int nThreadID; //Thread's ID oOj7y>Nm
boolean bDownOver = false; //Downing is over [;E~A
boolean bStop = false; //Stop identical wk'12r6=(-
FileAccessI fileAccessI = null; //File Access interface M yvyp
;]/emw=a
GW[g!66^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /&`sB|
{ f=f8)+5
this.sURL = sURL; y7?n;3U]CS
this.nStartPos = nStart; Pm Zb!|
this.nEndPos = nEnd; X,Q'Xe/
nThreadID = id; .0[ zZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YaWZOuxm
} ST*\Q
+5>*$L%8T`
1%R8q=_
public void run() WLB@]JvTBY
{ *T+Bjj;w
while(nStartPos < nEndPos && !bStop) f7mN,_Lt
{ -F+ )N$CW
zK5/0zMZ
ZYi."^l
try{ ev$\Ns^g$3
URL url = new URL(sURL); XlPi)3m4/S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^^O @ [_
httpConnection.setRequestProperty("User-Agent","NetFox"); zP F0M(
String sProperty = "bytes="+nStartPos+"-"; hS?pc<~`#
httpConnection.setRequestProperty("RANGE",sProperty); PU"C('AP
Utility.log(sProperty); bGO[P<<
6BnP"R.
[#}0)
InputStream input = httpConnection.getInputStream(); G1vg2'A
//logResponseHead(httpConnection); FM80F_G^z
[X"F}ph
feI%QnK)U
byte[] b = new byte[1024]; TH%J=1d
int nRead; 42Qfv%*c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Bc^%1
{ wd 4]Z0;
nStartPos += fileAccessI.write(b,0,nRead); s\CZ os&
//if(nThreadID == 1) A$H;2T5N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5\?\|*WT
} h}T+M BA%
;AjY-w
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Utility.log("Thread " + nThreadID + " is over!"); O>h,u[0
bDownOver = true; 3[RP:W@%
//nPos = fileAccessI.write (b,0,nRead); T@S\:P
} re$xeq\1P?
catch(Exception e){e.printStackTrace ();} Al0 i{.V
} '#;%=+=;
} ;$\?o
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"IjCuR;#
//打印回应的头信息 %YH+=b:uW
public void logResponseHead(HttpURLConnection con) npj_i /&g
{ 8n[6BF);
for(int i=1;;i++) 'pa>;{
{ W`qiPLk
String header=con.getHeaderFieldKey(i); 8BHtN
if(header!=null) Tx+Bkfj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G>>`j2:y
Utility.log(header+" : "+con.getHeaderField(header)); >`3wEJ"<
else 3Y L
break; Hju7gP=y}
} lU}y%J@
} QO-R>
>R9_;
Zs(I]^w;d
public void splitterStop() 6rx%>\UkS
{ vLc7RL
bStop = true; X:un4B}O
} `ZC{<eVJ}=
~"Kf+eFi
#lf3$Tm D
} w6PKr^
J#```cB
5)T=^"IHXi
/* \L-K}U>J
**FileAccess.java FRSz3^Aw
*//文件访问(定位，写) iPD5 KsAOA
package NetFox; `Wes!>Vh!
import java.io.*; wU9H=w^
hZ#ydI|
TSl:a &
public class FileAccessI implements Serializable{ RSK~<Y@]q{
o:p6[SGd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {N \ri{|
RandomAccessFile oSavedFile; (eG9b pqr
long nPos; t7t?xk!2
~)ZMGx
8Moe8X#3
public FileAccessI() throws IOException FR7DuH/f)
{ R>r@I_
this("",0); t,YnweH
} cJ}J4?
-=tf)
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public FileAccessI(String sName,long nPos) throws IOException \hm;p
{ rzR=% >
oSavedFile = new RandomAccessFile(sName,"rw"); 6;O fh
this.nPos = nPos; MM+xm{4l
oSavedFile.seek(nPos); gJ; *?Uq(
} @scy v@5)F
X\z`S##kj
AM[#AZv
public synchronized int write(byte[] b,int nStart,int nLen) MR) *Xh
{ ?$ft3p}
int n = -1; \~LwlOo%R
try{ ke+3J\;>
oSavedFile.write(b,nStart,nLen); (9"w{pnlLc
n = nLen; J'Z!`R|
} n!Ic.T3PA
catch(IOException e) Q)n6.%V/e
{ P0Q]Ds|
e.printStackTrace (); gB&8TE~Y
} t#fbagTON
17\5NgB
xrXfLujn%
return n; I3ZlKI
} %![%wI?
N=JZtf/i
-L.U4x
} NSsLuM=.
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z'W8t|m}Pb
/* C1x"q9|\`
**SiteInfoBean.java mMz^I7$
*/ 9AA_e ~y
package NetFox; EAdr}io
@hb K
DX*eN"z[
public class SiteInfoBean { rz@FUU:&
$jc&Tk#
dN8@ 0AMSf
private String sSiteURL; //Site's URL o\#C#NiT
private String sFilePath; //Saved File's Path 75^U<Hz-3{
private String sFileName; //Saved File's Name 9{A[n}
private int nSplitter; //Count of Splited Downloading File ^|P/D
-$x5[6bN
0LjF$3GpZ
public SiteInfoBean() g }%$VUSA
{//nSplitter的缺省值为5 +K@wh
//default value of nSplitter is 5 fMRv:kNAt
this("","","",5); C:?mOM#_
} dR^7d _!
Oi?+Z:lak
}[$qn|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $4*wK@xu
{ .# Jusd
sSiteURL= sURL; 5>S<9A|Q
sFilePath = sPath; aw3 oG?3I
sFileName = sName; l2&s4ERqSm
this.nSplitter = nSpiltter; VJ8"Q
]1^F
"1-gMob
} oZ/z{`
/^2&@P7
wT taj08D
public String getSSiteURL() A#&,S4Wi|
{ h&k*i
return sSiteURL; (59u<F
} BDO]-y
\qo}}I>e
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public void setSSiteURL(String value) ?k}"g$JFn
{ 8Hf:yG,
sSiteURL = value; &nRbI:R
} qgk-[zW#
.!B>pp(9
~+HZQv3Y
public String getSFilePath() |})7\o
{ >l$qE
return sFilePath; cD6T4
} S,*
<Rno;
/}ADV2sF
public void setSFilePath(String value) A_ftf7,
{ -(Z%?]+
sFilePath = value; 3jJd)C R
} ` 465 H
2JMMNpya
/_?y]Ly[r
public String getSFileName() ZJod=^T
{ 4)DI0b"
return sFileName; 88}=VS
} ,P T5-9 m
l>J>?b=x"[
4(hHp6}b
public void setSFileName(String value) ,lUroO^^
{ g%.;ZlK
sFileName = value; egd%,`
} PdkS3Hz
iVQ)hsW/
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public int getNSplitter() f\zu7,GU
{ Vt[Kr
return nSplitter; $lC*q
} i:@n6GW+iw
"h84D&V
G(*7hs
public void setNSplitter(int nCount) S+LS!b
{ HXg#iP^tv
nSplitter = nCount; VOa7qnh4:[
} #K4lnC2qz
} >}p'E9J?r
xV}ybRKV
q ?qpUPzD
/* ,5 A&
**Utility.java B S^P&TR!
*/ +J+[fbqX
package NetFox; (TF;+FRW
PIthv[F
@5)THYAx4
public class Utility { {0ozpE*(
g(b:^_Nep
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public Utility() tw*n+{]hi
{ Cbq|<p# #o
Z4ZR]eD
_l$1@
} WNa#X]*E)
L*'3f~@Q
//线程睡眠 8YLS/dN0 w
public static void sleep(int nSecond) /5s,< 0Kz
{ 7XDze(O5
try{ ZQ_&HmgRy
Thread.sleep(nSecond); vrr`^UB2
} :VvJx]
catch(Exception e) x$WdW+glZ-
{ l`' lqnhv
e.printStackTrace (); /iwL$xQQ
} -|/kg7IO\
} NA<6s]Cs.
gT=RJB
//日志 .o"FT~}z
public static void log(String sMsg) xtN=?WjVe0
{ * SHQ[L4{
System.err.println(sMsg); l}aJRG6U
} re%MT@L#
4or8fG
.%3qzOrN
public static void log(int sMsg) efnj5|JSV
{ E{#Y=
System.err.println(sMsg); J nzI- y
} 1oVjx_I5y
} L74Sx0nk=
28jm*Cl8
GO|EeM!iB
/* \.AI;^)X@]
**TestMethod.java L[LgQ7esQ
*/ ;i,:F`b~
package NetFox; !arTR.b\
6z2_b wo
eCI0o5U
public class TestMethod { >RL|W}tI4
/U1 jCLR'
J]=2] oI2
public TestMethod() w?db~"T
{ ///xx/weblogic60b2_win.exe UZqQ|3
try{ : ~R:[T2P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y9@DlK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =w/S{yC
SiteFileFetch fileFetch = new SiteFileFetch(bean); %x5zs ]4^
fileFetch.start(); [ ]LiL;A&
} "p[FFg
catch(Exception e){e.printStackTrace ();} 320g!r
?->&)oAh
VdfV5"
} pSml+A:
ap% Y}
h4 X>
public static void main(String[] args) H>/LC* 8-
{ MY$-D+#/`
new TestMethod(); U(t_uc5q
} iI.d8}A
} G"'[dL)N>
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