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)); -$WYj"
} l?Fb ='#
for(int i=0;i<nEndPos.length-1;i++) @)-$kk*
{ y^}6!>Ou:
nEndPos = nStartPos[i+1]; 5<ux6,E1{
} j'BMAn ?
nEndPos[nEndPos.length-1] = nFileLength; m q{];
} rORZerM
} d\ ~QBr?
dVFf.
=<NljOR4`
//启动子线程 *H.oP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yZ7,QsEsN
for(int i=0;i<nStartPos.length;i++) HfvTxaK
{ Ie4hhW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S}ECW,K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]f_6 '|5A
nStartPos,nEndPos,i); 9>g,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W"k8KODOY
fileSplitterFetch.start(); Ce")[<:
} 6'RrQc=q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gF5a5T,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Tp9-niW
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |)K]U
nEndPos = " + nFileLength); IrWD%/$H
// fileSplitterFetch[nPos.length-1].start(); S-'fS2
gW1b~( fD
%0mMz.f
//等待子线程结束 [_.5RPJP8
//int count = 0; mUz\ra;z
//是否结束while循环 K a(J52
boolean breakWhile = false; #~.w&~:
!Wy[).ZAf
O=dJi9;`#_
while(!bStop) A6pjRxg
{ LI6hEcM=
write_nPos(); Wf&W^Q
Utility.sleep(500); BZXUwqEh
breakWhile = true; =T7A]U]
4)<~4 '
(Gw,2-A
for(int i=0;i<nStartPos.length;i++) }Iz7l{al
{ _+^ 2^TW
if(!fileSplitterFetch.bDownOver) S9>0t0
{ =l0Jb#d
breakWhile = false; }QsZ:J.
break; 2d {y M(=(
} sqS=qC
} fz3lV
if(breakWhile) ~35U]s@v
break; /2HN>{F^Y
?l$Nf@-
7zv1wb
//count++; ]+m/;&0
//if(count>4) m/@<c'i
// siteStop(); 9Y<#=C
} ]d]JXt?)i
UEzb^(8>
,E$@=1)
System.err.println("文件下载结束！"); _C+b]r/E
} XbZ*&
catch(Exception e){e.printStackTrace ();} 60)iw4<wf
} hAjM1UQ,Y
}irn'`I
bC3 F
//获得文件长度 4ON_$FUe
public long getFileSize() _%x4ty
{ ]Y| 9?9d
int nFileLength = -1; s#S%#LM
try{ vc]cNz:mQ
URL url = new URL(siteInfoBean.getSSiteURL()); *\o/q[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1<h>B:
httpConnection.setRequestProperty("User-Agent","NetFox"); Vm|Y$C
{" 4e+y
ad_`x
int responseCode=httpConnection.getResponseCode(); \6 93kQ
if(responseCode>=400) ee/&/Gt
{ 2EK%N'H
processErrorCode(responseCode); $ A9%UhV
return -2; //-2 represent access is error f(eQ+0D
} nWvuaQ0}
V&|!RxWK
rJo"fx
String sHeader; /2m?15c+
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6y5A"-
for(int i=1;;i++) thqS*I'#g
{ NKmoG\*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R+~cl;#G6
//Utility.log(in.readLine()); %,iIpYx
sHeader=httpConnection.getHeaderFieldKey(i); 62>zt2=
if(sHeader!=null) P\&! ]
{ KHDZ
if(sHeader.equals("Content-Length")) a@pz*e
{ )kJH5/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0'r%,0
break; l6u&5[C
} _NcYI
} oiH|uIsqR
else #DjCzz\
break; [,aqQ6S
} JNFIT;L
} BvU"4d;x
catch(IOException e){e.printStackTrace ();} j2Pn<0U
catch(Exception e){e.printStackTrace ();} 1'4J[S\cM
nCKbgM'"
gs W0
Utility.log(nFileLength); YUdxG/~'
NA.1QQ;e
T`9-VX;`
return nFileLength; TFepxF
} CVi`bO4\
YOAn4]j
c:l]=O
//保存下载信息（文件指针位置） 3?E&}J<n
private void write_nPos() yxBUj*3
{ #2:a[ ~Lf
try{ jb /8?7
output = new DataOutputStream(new FileOutputStream(tmpFile)); /"ymZI!k\
output.writeInt(nStartPos.length); F#{gfh
for(int i=0;i<nStartPos.length;i++) (Bo bB]~a
{ ;p ]y)3
// output.writeLong(nPos); w&BGJYI
output.writeLong(fileSplitterFetch.nStartPos); ntP|\E
output.writeLong(fileSplitterFetch.nEndPos); -~4+w
} SjdZyJa
output.close(); R1-k3;v^
} J@9}`y=K
catch(IOException e){e.printStackTrace ();} ~^vC,]hU
catch(Exception e){e.printStackTrace ();} -K[782Q
} p[2GkP
jvVi%k
b8f+,2Tk
//读取保存的下载信息（文件指针位置） htPqT,L
private void read_nPos() ^I]{7$6^
{ #'hLb
try{ a9~"3y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :h:@o h_=
int nCount = input.readInt(); somfv$'B
nStartPos = new long[nCount]; )uLr?$qe
nEndPos = new long[nCount]; 9B+wYJp
for(int i=0;i<nStartPos.length;i++) +/?iCmW
{ s~},y]YV
nStartPos = input.readLong(); E-1"+p
nEndPos = input.readLong(); ^UA(HthY
} ]Fb0Az
input.close(); %TrF0{NR90
} xiyxrR;
catch(IOException e){e.printStackTrace ();} \O7J=6fn
catch(Exception e){e.printStackTrace ();} XV'fW~j\
} 89cVJ4]g~!
!~lW3
l>v{
private void processErrorCode(int nErrorCode) *wi}>_\
{ Q;nAPS
System.err.println("Error Code : " + nErrorCode); mo1 puU
} >m_v5K
dZ:r&Qa
c#b:3dXx9
//停止文件下载 \%,&~4 !
public void siteStop() Y~n`~(
{ fn9#>~vrD
bStop = true; s%;<O:x8o
for(int i=0;i<nStartPos.length;i++) "D*Wi7
fileSplitterFetch.splitterStop(); &B!%fd.'
w5]l1}rl
:k46S<RE
} %d: A`7x
} A2x;fgi
//负责部分文件的抓取 3z{S}~
**FileSplitterFetch.java ?kt=z4h9(
*/ jnoL2JR[=-
package NetFox; 30FykNh
~_!ts{[E
Xz;b,C&*t
import java.io.*; .F0]6#(
import java.net.*; a%hGZCI
>Csbjf6
^Y^"'"
public class FileSplitterFetch extends Thread { c!&Qj
{@M14)-x>_
FQf#*
String sURL; //File URL Xy#VQ{!
long nStartPos; //File Snippet Start Position JZ`L%
long nEndPos; //File Snippet End Position .#^0pv!
int nThreadID; //Thread's ID xKp0r1}
boolean bDownOver = false; //Downing is over |0{ i9.=
boolean bStop = false; //Stop identical Kla:e[{
FileAccessI fileAccessI = null; //File Access interface um8AdiK
R9.HD?H@
U 5`y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @~jxG%y86
{ ~uPk
this.sURL = sURL; >zL|8f
this.nStartPos = nStart; ~Sy-gaJ
this.nEndPos = nEnd; I{dl%z73
nThreadID = id; i=QqB0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +Z?[M1g
} 6b:DJ
~HP LV
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public void run() ;.Zh,cU
{ N4[E~-
while(nStartPos < nEndPos && !bStop) :$"7-a%f
{ R'EW7}&
U($^E}I2(
GhnE>d;i
try{ $P?{O3:V
URL url = new URL(sURL); o_yRn16
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xQz#i-v
httpConnection.setRequestProperty("User-Agent","NetFox"); ^now}u9S6
String sProperty = "bytes="+nStartPos+"-"; A9BxwQU#
httpConnection.setRequestProperty("RANGE",sProperty); @;9()ad
Utility.log(sProperty); xbC~C~#
*1;23BiH-
#J+\DhDEPO
InputStream input = httpConnection.getInputStream(); ^`&HWp
//logResponseHead(httpConnection); |t\KsW
ci7~KewJ*
_hoAW8i
byte[] b = new byte[1024]; 0]a15
int nRead; u~71l)LA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'P/taEi=R
{ a!.!2a&t
nStartPos += fileAccessI.write(b,0,nRead); ;4d.)-<No_
//if(nThreadID == 1) *IlQ5+3I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yv${M u
} 0^>E`/
v:P!(`sF
hCLk#_
Utility.log("Thread " + nThreadID + " is over!"); TczXHT}G
bDownOver = true; GUCM4jVT^
//nPos = fileAccessI.write (b,0,nRead); d]k='
} zXgkcq)
catch(Exception e){e.printStackTrace ();} #D:RhqjK
} |!re8|JV_
} \|!gPc%s
/:6Q.onmLn
$f(agG]
//打印回应的头信息 G4yUC<TqBP
public void logResponseHead(HttpURLConnection con) 5TET<f6R
{ &V;x 4
for(int i=1;;i++) sUda
{ xL&PJ /'
String header=con.getHeaderFieldKey(i); ^%zNa6BL
if(header!=null) )b (X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kt<@H11
Utility.log(header+" : "+con.getHeaderField(header)); #! @m y
else g!`BXmW
break; Q}z{AZ
} 0(vdkC4\A
} 7h1"^}M&
M;@Ex`+?i
| W?[,|e
public void splitterStop() i-V0Lm/
{ -t b;igv
bStop = true; aZ/yCS7
} *C/KM;&
/T#o<D
gDc]^K4>
} SW-0h4
7`+UB>8
wKrdcWI,Z
/* /p[y1
**FileAccess.java 7?]!Ecr"
*//文件访问(定位，写) P59uALi
package NetFox; c.6QhE
import java.io.*; DsG !S*
Vdy\4 nu(
}Y$VB%&Hy
public class FileAccessI implements Serializable{ q\G{]dz?R
j>g9\i0O1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +9}' s{
RandomAccessFile oSavedFile; 0, "ZV}
long nPos; JSUzEAKe
2?pM5n
R''Sfz>8
public FileAccessI() throws IOException ;>'SV~F
{ (aBP|rxg
this("",0); 'iDu0LX
} X{|k<^:
SFOQM*H
'U*udkn 2]
public FileAccessI(String sName,long nPos) throws IOException ?xf~!D
{ kz|[*%10
oSavedFile = new RandomAccessFile(sName,"rw"); )rS^F<C
this.nPos = nPos; 2PI #ie4
oSavedFile.seek(nPos); b__n~\q_
} OT"lP(,
~CJYQFt
cxk=| ?l
public synchronized int write(byte[] b,int nStart,int nLen) "vvFq ,c
{ G)K9la<p
int n = -1; !zl/0o
try{ "9.6\Y\*
oSavedFile.write(b,nStart,nLen); ~v,!n/('
n = nLen; hXBqz9
} @)06\h
catch(IOException e) Q,O]x#
{ <6gU2@1
e.printStackTrace (); M`q#,Y?3^I
} =I{S;md
uJ7,rq
:nTkg[49pJ
return n; ud!r*E
} C=M?
FJ nG<5Rh
MEDskvBG
} AZ}%MA;q
/}[zA@
..]B9M.
/* p$&_fzb
**SiteInfoBean.java oF`-cyj"
*/ 8APTk
package NetFox; Rf&^th}TH
HL|0d }
>hh"IfIZ4
public class SiteInfoBean { mT}Aje-L
v UJ sFR
5,g$|,Shv
private String sSiteURL; //Site's URL `<bCq\+`
private String sFilePath; //Saved File's Path =]6_{#Z<
private String sFileName; //Saved File's Name D_]i/ F%
private int nSplitter; //Count of Splited Downloading File vs*_;vx
%Tk}sfx
I*%&)Hj~
public SiteInfoBean() gDgP;id
{//nSplitter的缺省值为5 CA'hvXb.
//default value of nSplitter is 5 P2s^=J0@
this("","","",5); `7+tPbjs
} CAcOWwDm
sz){uOI
q|m#IVc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0R.Gjz*Q
{ ntd ":BKi
sSiteURL= sURL; Nj"_sA p
sFilePath = sPath; ZzSJm+&'
sFileName = sName; !NQf< ch
this.nSplitter = nSpiltter; GIJV;7~
C%qtCk_cN
`V$cz88b
} ZhxfI?i)l
=rE`ib
$=QNGC2+
public String getSSiteURL() jCdZ}M($
{ 9QO!vx
return sSiteURL; a?f5(qW3
} e/ppZ>
5k_Mj*{6
Z.Lx^h+U
public void setSSiteURL(String value) WcQZFtW
{ +K @J*W 1
sSiteURL = value; u^;sx/
} %6vMpB`g
EC:x,i
sP=2NqU3Q
public String getSFilePath() BUboP?#%)
{ AF07KA#
return sFilePath; Qt)7mf
} t~udfOvY
H znI R
:5n"N5Go
public void setSFilePath(String value) +$Ddd`J'
{ 4l#T_y
sFilePath = value; SvCK;$:
} w2RESpi
$Adp
M?:f^
public String getSFileName() vs)HbQ
{ QB oZCLv
return sFileName; '3Y0D1`v
} \^^hG5f
4%Z\G@0<'
_dB0rsCnU%
public void setSFileName(String value) 3L\s8O
{ O=9VX
sFileName = value; (&a3v
} \5v=pDd4g
({}O M=_
!F}J+N=}
public int getNSplitter() &'oacV=
{ 5Rt0h$_J
return nSplitter; 1f bFNxo8M
} ~]D\&D9=?
(urfaZ;@+
Vtc)/OH
public void setNSplitter(int nCount) *RqO3=
{ q#':aXcv"
nSplitter = nCount; LU 5 `!0m
} hBs>2u|z9
} K.sj"#D
QL|:(QM
E|6Z]6[
/* kcZ;SYosj
**Utility.java :@z5& h
*/ *X=f
package NetFox; \?Oly171
'KIi!pA.
4jZi62
public class Utility { jd*%.FDi{
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9_CA5?y$:
public Utility() 4<K ,w{I
{ LMhY"/hAXa
#uDBF
D;T r
} FZ'>LZ
l%)=s~6z
//线程睡眠 yvH#1F`{q
public static void sleep(int nSecond) %<#$:Qb.
{ QP-<$P;~
try{ -EX3' [*'
Thread.sleep(nSecond); N_WA4?rB
} \]d*h]Hms
catch(Exception e) b~jvmcr
{ Rcm(Y7
e.printStackTrace (); h-v&I>
} |jCE9Ve#
} 2w.9Q (Sn
]FnrbQ|
//日志 7 +W?Qo
public static void log(String sMsg) } k%\
{ ~IN$hKg^
System.err.println(sMsg); yP=isi#dDY
} {Z{NH:^
qh'f,#dI}
H ]N/Y{
public static void log(int sMsg) rF j)5~
{ '<E8<bi
System.err.println(sMsg); Xrzh*sp
} <)*g7
} Q`wA"mw6k
G cLp"
NByN}e
/* 9j>sRE1
**TestMethod.java )9W#5V$
*/ ~uD;_Y=u)r
package NetFox; Q; /!oA_
V{^fH6;[
Zp(P)Obs#
public class TestMethod { N55=&-p
nN]vu
5FR#_}k]_F
public TestMethod() y&I|m
{ ///xx/weblogic60b2_win.exe ;[\2/$-
try{ Gw\HL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r.G/f{=<@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); KD3To%
SiteFileFetch fileFetch = new SiteFileFetch(bean); :?XHZ
fileFetch.start(); eR 2T<7G
} #dm@%~B{.
catch(Exception e){e.printStackTrace ();} +(k)1kCMn
q,>F#A'
WD do{
} X}QmeY[0I
(7#lN
q^+NhAMz
public static void main(String[] args) pvdZ>D-IU
{ HG6{`i
new TestMethod(); jW0z|jr
} =}o>_+"
} \ A UtGP
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