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)); r8t}TU>C
} j7Yu>cr
for(int i=0;i<nEndPos.length-1;i++) h]5(].
{ Q^P}\wb>
nEndPos = nStartPos[i+1]; 9 &dtd
} S3C]AhW;
nEndPos[nEndPos.length-1] = nFileLength; )rIwqUgp6\
} j.[.1G*("
} zF`0J
>.Pnkx*
L8@f-Kk
//启动子线程 c`)\Pb/O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; KWbI'}_z
for(int i=0;i<nStartPos.length;i++) ;HfmzY(
{ ~p6 V,Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EgEa1l!NSQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &C5_g$Ma.Z
nStartPos,nEndPos,i); IV~>I-rd
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +zqn<<9
fileSplitterFetch.start(); 7uqzm
} A;q9rD,_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "m):Y;9iQ?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZuzEg*lb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YsC>i`n9
nEndPos = " + nFileLength); ,C\i^>=
// fileSplitterFetch[nPos.length-1].start(); Gq)]s'r2
#Qw0&kM7I
.fqN|[>
//等待子线程结束 c1(RuP:S
//int count = 0; dZl5Ic
//是否结束while循环 )N{Pw$l_
boolean breakWhile = false; G{~J|{t\yz
(Bb5?fw
'`[&}R
while(!bStop) oi7@s0@
{ E:_ZA
write_nPos(); nt;m+by
Utility.sleep(500); 3)wN))VBX
breakWhile = true; b<[Or^X ]
*uRBzO}
PA{PD.4Du
for(int i=0;i<nStartPos.length;i++) ^]Y>[[
{ 20h} [Q(
if(!fileSplitterFetch.bDownOver) 4&lv6`G `
{ D(op)]8
breakWhile = false; C\3rJy(VJ
break; FW;?s+Uyx
} ]Jg&VXrH
} S&5&];Ag
if(breakWhile) Wx%H%FeK
break; *\a4wZ6<3
wD}l$& +
& bm 1Fz
//count++; BN5[,J
//if(count>4) |)DGkOtd
// siteStop(); dh\'<|\K
} 8mrUotjS
F@jZ ho
tmYz R%i
System.err.println("文件下载结束！"); ;W )Y OT
} <]t%8GB2V
catch(Exception e){e.printStackTrace ();} z]y.W`i
} kPG-hD
%g$o/A$
?#G$=4;i
//获得文件长度 LKB$,pR~1l
public long getFileSize() @l5"nBs<_:
{ ,.8KN<A2]'
int nFileLength = -1; :uS\3toj
try{ ;%9|kU
URL url = new URL(siteInfoBean.getSSiteURL()); Y;M|D'y+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]IQ&>z}<
httpConnection.setRequestProperty("User-Agent","NetFox"); a$OE0zn`
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int responseCode=httpConnection.getResponseCode(); Tn e4
if(responseCode>=400) Wq&if_
{ k@J&IJ
processErrorCode(responseCode); ,AFu C<
return -2; //-2 represent access is error BoWg0*5xb
} xwq (N_
nPl?K:(
ql{OETn#
String sHeader; #&aqKVY
'[:D$q;
Cctu|^V
for(int i=1;;i++) }@+0/W?\.
{ :U%W%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $k%2J9O
//Utility.log(in.readLine()); %s|Ely)
sHeader=httpConnection.getHeaderFieldKey(i); 9~XAq^e
if(sHeader!=null) "?xHlYj@+
{ (m/G(wg
if(sHeader.equals("Content-Length")) ,!y$qVg'\f
{ sIGMA$EK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xsbE TP?
break; %T%sGDCV
} KL57#gV
} <0&*9ZeD
else JIOR4'9
break; zKJ#`OhT
} )23H1
} [D4SW#
catch(IOException e){e.printStackTrace ();} BLiF 5
catch(Exception e){e.printStackTrace ();} k"iOB-@B+
_op}1
X51:
Utility.log(nFileLength); |&)dh<
{@{']Y
9vc2VB$
return nFileLength; {qJ1ko)$
} jcf7n`L
`0gyr(fES
,i`,Oy(BI
//保存下载信息（文件指针位置） A[{yCn`tM
private void write_nPos() F/kWHVHU[
{ 29] G^f>
try{ EUX\^c]n
output = new DataOutputStream(new FileOutputStream(tmpFile)); )'cMYC
output.writeInt(nStartPos.length); @:vwb\azVD
for(int i=0;i<nStartPos.length;i++) DA,?}
{ S g![Lsj
// output.writeLong(nPos); Ka V8[|Gn,
output.writeLong(fileSplitterFetch.nStartPos); 4!yzsPJL
output.writeLong(fileSplitterFetch.nEndPos); !F'YDjTot
} *P=VFP
output.close(); .?sx&2R2
} jLm ;ty2;
catch(IOException e){e.printStackTrace ();} ~HsJUro
catch(Exception e){e.printStackTrace ();} ^k">A:E2
} z$. 88^
Om2d.7S
x g
//读取保存的下载信息（文件指针位置） YPk fx
private void read_nPos() 7[XRd9a5(
{ >KhOz[Zg
try{ bK&+5t&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <`r>h
int nCount = input.readInt(); h3 }OX{k
nStartPos = new long[nCount]; VjZ|$k
nEndPos = new long[nCount]; 4vB<fPN
for(int i=0;i<nStartPos.length;i++) Eo]xNn/g
{ B[?Ng}<g`
nStartPos = input.readLong(); 7~.9=I'A
nEndPos = input.readLong(); `+:`_4
} ]Q)OL
input.close(); v`Oc,
} <R=Zs[9M1
catch(IOException e){e.printStackTrace ();} R!gEwTk
catch(Exception e){e.printStackTrace ();} h J)h\
} .4!=p*Y
tFOhL9T
cIOlhX@
private void processErrorCode(int nErrorCode) p6!x=cW
{ `7V]y-
System.err.println("Error Code : " + nErrorCode); R8Fv{7]c
} 'e'cb>GnA
Cjlk
z_4J)?3
//停止文件下载 BuXqd[;K%
public void siteStop() $}<e|3_
{ PIS2Ed]
bStop = true; VQOezQs\
for(int i=0;i<nStartPos.length;i++) <$Yd0hxjU
fileSplitterFetch.splitterStop(); oV78Hq6
59;KQ
1f=gYzuO)
} pG;U2wE
} w@w(-F!%l
//负责部分文件的抓取 t&e{_|i#+
**FileSplitterFetch.java ~6LN6}~|.
*/ )|#sfHv7
package NetFox; &`2)V;t
5M*:}*
]Gq !`O1
import java.io.*; }`m/bgtFX
import java.net.*; /R wjCUf
0{-q#/
_u QOHwn
public class FileSplitterFetch extends Thread { tf`^v6m%]
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Se =`N
String sURL; //File URL ,.FxIl]
long nStartPos; //File Snippet Start Position %6f*{G w
long nEndPos; //File Snippet End Position /aZ`[m2
int nThreadID; //Thread's ID z*%q@]ym
boolean bDownOver = false; //Downing is over smo~7;
boolean bStop = false; //Stop identical fVpMx4&F
FileAccessI fileAccessI = null; //File Access interface ; kI134i=
ge8ZsaiU
amY!qg0P*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {&1/V
{ f9{Rb/l!BQ
this.sURL = sURL; [Y|t]^M
this.nStartPos = nStart; Z4 =GMXj
this.nEndPos = nEnd; JY(WK@
nThreadID = id; 1#+S+g@#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p H2Sbs:Tk
} v):Or'$~M
;>7De8v@@
Q*~]h;6\{d
public void run() z!9-:
{ >e$PP8&i_T
while(nStartPos < nEndPos && !bStop) .eVG:tl\
{ t;\Y{`
7WZ+T"O{I
ePo}y])2
try{ {9q4)R}G
URL url = new URL(sURL); ##"HF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Oxd]y1
httpConnection.setRequestProperty("User-Agent","NetFox"); ]~3V}z,T*
String sProperty = "bytes="+nStartPos+"-"; -6B4sZpzD
httpConnection.setRequestProperty("RANGE",sProperty); 8FY?!C
Utility.log(sProperty); 6qnzBA7
$yNS pNmT0
C1QA)E['V
InputStream input = httpConnection.getInputStream(); 0flRh)[J
//logResponseHead(httpConnection); $*fMR,~t&
|@4' <4t
7hPY_W y
byte[] b = new byte[1024]; zy }$i?
int nRead; sd|).;s}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1p=]hC
{ qY!Zt_Be6
nStartPos += fileAccessI.write(b,0,nRead); HN|%9{VeB
//if(nThreadID == 1) 5$C-9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 11;MN
} #AQV(;r7@
/IMFO:c
$qj2w"'
Utility.log("Thread " + nThreadID + " is over!"); I b5rqU\
bDownOver = true; Ig>(m49d
//nPos = fileAccessI.write (b,0,nRead); %1+4_g9
} Xc&9Glf
catch(Exception e){e.printStackTrace ();} )+9Uoe~6
} h@ryy\9
} EXqE~afm2
}0Ed]
e$rZ5X
//打印回应的头信息 b d!Y\OD
public void logResponseHead(HttpURLConnection con) },-H"Qs
{ I-l_TpM)
for(int i=1;;i++) &{t,'[ u
{ M9%$lCl
String header=con.getHeaderFieldKey(i); 5:_}zu|!u
if(header!=null) e+fN6v5pU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1bwOmhkS
Utility.log(header+" : "+con.getHeaderField(header)); ^^ixa1H<
else ' S/gmn
break; fe_5LC"
} 3%b6{ie/=
} GnJt0{
G]&qx`TBK
}Jj}%XxKs
public void splitterStop() nAlQ7'
{ K[zVa
bStop = true; bV3|6]k^
} R.<g3"Lm>
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e$Pj.>-<=
} mQ"-,mMI
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/* [ub e6
**FileAccess.java KF:78C
*//文件访问(定位，写) \YrUe1
package NetFox; ,r_Gf5c
import java.io.*; bW(0Ng
4;2uW#dG"
e~"U @8xk~
public class FileAccessI implements Serializable{ (X*^dO
MkXmA`cP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y(Hs#Kn{
RandomAccessFile oSavedFile; QQc -Ya!v
long nPos; 1EX;MW-p<T
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*MW\^PR?
public FileAccessI() throws IOException >uEzw4w
{ &s>Jb?_5Mx
this("",0); S)"Jf?
} ,f?*{Q2
{(Es(Sb}c
k)TpnH! "
public FileAccessI(String sName,long nPos) throws IOException XfIJ4ZM5
{ 5~DJWi,
oSavedFile = new RandomAccessFile(sName,"rw"); Xne1gms
this.nPos = nPos; uHRsFlw
oSavedFile.seek(nPos); !&@615Vtw
} WcbiqxK7-
t\O16O7S
}4X0epPp;:
public synchronized int write(byte[] b,int nStart,int nLen) rEz^
{ zX i'kB
int n = -1; i SQu#p@
try{ 1s;Saq+
oSavedFile.write(b,nStart,nLen); ~v6D#@%A
n = nLen; @oGcuE
} < I``&>
catch(IOException e) DzRFMYBR
{ +Vdpy(
e.printStackTrace (); X2'0PXv>!
} Q22 GIr
<9b&<K:
V>3X\)qu
return n; )0k53-h&
} @IZnFHN
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ql~J8G9
} e&>2 n
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dqcL]e
/* 8H`[*|{'
**SiteInfoBean.java MiX43Pk]
*/ RT8 ?7xFc
package NetFox; w&.aQGR#
Rf% a'b
05^h"
public class SiteInfoBean { yaX iE_.
qmP].sA
B`sAk %
private String sSiteURL; //Site's URL tO&^>&;5
private String sFilePath; //Saved File's Path DVeE1Q
private String sFileName; //Saved File's Name asqV~n
private int nSplitter; //Count of Splited Downloading File iN.n8MN=I
zKK9r~ M
bW:!5"_{H
public SiteInfoBean() ]I6 J7A[
{//nSplitter的缺省值为5 |1Z)E+q*:
//default value of nSplitter is 5 =i3n42M#
this("","","",5); 5`_SN74o
} dgP3@`YS
J9 I:Q<;
u]G\H!WkQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A?0Nm{O;3v
{ f)<6
sSiteURL= sURL; K.yb ^dg5
sFilePath = sPath; [PbOfxxgA
sFileName = sName; o;RI*I
this.nSplitter = nSpiltter; kSo"Ak!
$NO&YLS@
;9'OOz|+1
} ,iwp,=h=
M'l ;:
8JUwf
public String getSSiteURL() -%4,@ x`
{ ,wPr"U+7
return sSiteURL; #Rr%:\*
} >KKMcTOYY
{fp[BF
NyuQMU
public void setSSiteURL(String value) S`]k>' l
{ Q=dy<kg']
sSiteURL = value; -D~%|).'
} |vzl. ^"-
h@wgd~X9
HkVB80hv
public String getSFilePath() !Xw5<J3L-
{ Uoix
return sFilePath; f`66h M[
} .5{ab\_af
wwcBsJ1{
l}M!8:UzU
public void setSFilePath(String value) 7Fsay+a
{ dUdT7ixo
sFilePath = value; |! "eWTJ
} Yz)qcU
}SCM I4\
q-d:TMkc
public String getSFileName() ?|Zx!z ($
{ ""~ajy
return sFileName; UJ6v(:z<
} ?!/kZM_ts
/; 85i6
jmW7)jT8:
public void setSFileName(String value) sdmT
{ ENY+^7
sFileName = value; #:%/(j
} @pU)_d!pJ
aC)!T
Wo=jskBrQ
public int getNSplitter() ;i:d+!3XwC
{ y4fdq7i~}9
return nSplitter; "g8M0[7e3
} uY'HT|@:{
NQ2E
)w%!{hn
public void setNSplitter(int nCount) VVOd]2{
{ l1Fc>:o{
nSplitter = nCount; 5l*&>C[(i
} iOO)Q\
} iAU@Yg`pt
du^J2m{f
bA->{OPkT
/* (Ep\Z 6*
**Utility.java 7D5]G-}x.
*/ #Mw8^FST
package NetFox; i~J'%a<Qp
f& '
VP]%Hni]
public class Utility { HyWCMK6b
Th%Sjgsn
HHsmLo c4
public Utility() Z?QC!bWb
{ ^y%T~dLkp'
[cp+i^f
L;I]OC^J
} JaGtsi9%.
~$?ZK]YOrx
//线程睡眠 XOS[No~
public static void sleep(int nSecond) I2 P@L?h
{ E^eVvP4uC@
try{ z' >_Mc6
Thread.sleep(nSecond); E~oOKQ5W
} Jg|XH L)
catch(Exception e) Jze:[MYS
{ 9-*uPK]m9
e.printStackTrace (); s!7y
} }U"&8%PZr
} (JFWna0@
yaH Zt`Y
//日志 B_m8{44zM
public static void log(String sMsg) NHZz _a=
{ !d0kV,F:
System.err.println(sMsg); I&W=Q[m
} QB'aON\S
Hja3a{LH
ut7zVp<"
public static void log(int sMsg) 81 sG
{ fS78>*K
System.err.println(sMsg); j+ 0I-p
} v #j$;
} +!.^zp21
Qn)a/w-
XuM'_FN`A<
/* Qjv}$`M
**TestMethod.java ;@Y;g(bw:
*/ GDiBl*D
package NetFox; 1NA.nw.
%aVq+kC h
68WO~*
public class TestMethod { lp%pbx43s
IKilr'
Vb]=B~^`
public TestMethod() E92KP?i
{ ///xx/weblogic60b2_win.exe [j/9neaye
try{ z/@slT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A@{PZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K:#I
SiteFileFetch fileFetch = new SiteFileFetch(bean); =R$u[~Xl2X
fileFetch.start(); Iom'Y@x
} nazZ*lC
catch(Exception e){e.printStackTrace ();} A0 C,tVd
<FkFs{(t
]Wlco
} gu.}M:u
!9VY|&fHe
hH8oyIC
public static void main(String[] args) q Y?j#fzi
{ 4*cEag
new TestMethod(); =|y9UlsD
} nBSYsp{
} wc^tgE
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