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)); DP6>fzsl
} s$ZKd
for(int i=0;i<nEndPos.length-1;i++) neBcS[
{ /I~(*X
nEndPos = nStartPos[i+1]; $,8}3R5}
} 8;<3Tyjzu
nEndPos[nEndPos.length-1] = nFileLength; "NvB@>S
} g$T% C?
} HLb`'TC3r+
zW:r7 P.
+2JC**)I
//启动子线程 %(ms74R+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e3=-7FU
for(int i=0;i<nStartPos.length;i++) 20`QA u)'
{ r}M2t$nv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9?I?;l{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EXizRL-9o
nStartPos,nEndPos,i); uGY(`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LA4,o@V`
fileSplitterFetch.start(); vT;~\,M
} Cm%xI&Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `%$l b:e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w\%AR1,rs
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c+N\uG4
nEndPos = " + nFileLength); !n`Y^
// fileSplitterFetch[nPos.length-1].start(); E6+ 6
+z O.|`+
z+{Q(8'b]
//等待子线程结束 0NMmN_Lr
//int count = 0; ]EfM;'j[
//是否结束while循环 ,r,$x4*
boolean breakWhile = false; ;dquld+q
8],tGMu
q{2 +Inf#:
while(!bStop) -`ss7j&b3
{ Co^GsUJ
write_nPos(); LNOz.2fr>
Utility.sleep(500); -:|t^RM;FT
breakWhile = true; 4Ixu%
h:Hpz
v{O(}@
for(int i=0;i<nStartPos.length;i++) &H:2TL!
{ 'M=V{.8U
if(!fileSplitterFetch.bDownOver) r%FfJM@!
{ c3!YA"5
breakWhile = false; &w{: qBa
break; =q<t,UP8
} wvPS0]
} ^-g-]?q
if(breakWhile) B j z@X
break; 8^5@J)R8
m:]60koz]o
LLd5Z44v
//count++; zc&i 4K
//if(count>4) (3QG
// siteStop(); >"<<hjKJ
} 8?G534*r@2
7"p%c`*;
[w?v !8l
System.err.println("文件下载结束！"); uU!}/mbo
} "#=WD
catch(Exception e){e.printStackTrace ();} li
} fT0+inRG
*ulkqpO
;{Tf:j'g
//获得文件长度 }HxC~J"
public long getFileSize() W3]?>sLE*
{ 6GsB*hW
int nFileLength = -1; kA{eT
try{ 9k3RC}dEr
URL url = new URL(siteInfoBean.getSSiteURL()); gi JjE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p&W{g$D>
httpConnection.setRequestProperty("User-Agent","NetFox"); f!13Ob<8r
.Gn-`
* %w8bB
int responseCode=httpConnection.getResponseCode(); I0v4TjHH
if(responseCode>=400) UY/qI%#L#,
{ FV5~sy
processErrorCode(responseCode); 2i~zAD'
return -2; //-2 represent access is error N&]_U%#Q
} +J <<me4
2A(IsUtqO:
DNGj81'c
String sHeader; Fg^Z g\X3
+W^$my)<
4&wwmAp^
for(int i=1;;i++) g%%j"Cz1
{ df7xpV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oWV^o8& GH
//Utility.log(in.readLine()); /m8&E*+T1
sHeader=httpConnection.getHeaderFieldKey(i); b =R9@!
if(sHeader!=null) K yDPD'
{ yN9setw*,M
if(sHeader.equals("Content-Length")) a"whg~
{ DUWSY?^c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aSQvtv)91
break; ;\rKkH"K8n
} {:ZsUnzm
} OJXK]dZ
else \>)#cEX5
break; 1MxO((k
} #GIjU1-
} )|IMhB+4
catch(IOException e){e.printStackTrace ();} (x/xqDpmBS
catch(Exception e){e.printStackTrace ();} ]C5/-J,F
2M*84oh8P
LNI]IITx/
Utility.log(nFileLength); lJdwbuB6
^u$?& #
1wt(pkNk
return nFileLength; _OvIi~KW+
} H\<^p",`
=O'>H](Q
TmUN@h
//保存下载信息（文件指针位置） n--w-1
private void write_nPos() `Uy4>?
{ 1D2Yued
try{ ,&0iFUwN_
output = new DataOutputStream(new FileOutputStream(tmpFile)); U_ *K%h\m
output.writeInt(nStartPos.length); _aK4[*jnqh
for(int i=0;i<nStartPos.length;i++) S%2qX"8
{ }o2e&.$4d
// output.writeLong(nPos); +~!\;71:f
output.writeLong(fileSplitterFetch.nStartPos); M}qrF~
output.writeLong(fileSplitterFetch.nEndPos); d D;r35h=
} :y3e-lr
output.close(); o 76QQ+hP
} OE5JA8/H
catch(IOException e){e.printStackTrace ();} [hXnw'Im/
catch(Exception e){e.printStackTrace ();} F8>J(7On
} K&UTs$_cI
31`Eq*Y)4
lWWy|r'il
//读取保存的下载信息（文件指针位置） fSw6nEXn
private void read_nPos() B'~CFj0W%=
{ kqt.?iJw
try{ YZQF*fj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]hjA,p@Q
int nCount = input.readInt(); X'.*I])
nStartPos = new long[nCount]; *k<{nj@y
nEndPos = new long[nCount]; +WB';D
for(int i=0;i<nStartPos.length;i++) Y^9b>H\2
{ 9P\R?~3
nStartPos = input.readLong(); K4j2xSGeo
nEndPos = input.readLong(); CyV(+KBe_
} 7)
input.close(); ZFa<{J<2
} -|YDKcL
catch(IOException e){e.printStackTrace ();} mxkv{;ad
catch(Exception e){e.printStackTrace ();} f1TYQ?e
} CZ}%\2>-v
g"|Z1iy|9
V jZx{1kCR
private void processErrorCode(int nErrorCode) 8bW,.to(?x
{ iYBp"+#2
System.err.println("Error Code : " + nErrorCode); CT#u+]T
} P=PVOt@ b
VY_<c98v
2/.I6IbL
//停止文件下载 drW}w+!
public void siteStop() KdU&q+C^
{ ,'^^OLez
bStop = true; `cn}}1Lg]
for(int i=0;i<nStartPos.length;i++) i[rXs/]
fileSplitterFetch.splitterStop(); Lk:Sju
{>8u/
L__J(6,V2
} Q|i`s=|
} O&ZVu>`g
//负责部分文件的抓取 #SIIhpjA(
**FileSplitterFetch.java ZGbY
*/ lMRy6fzI
package NetFox; x&YcF78
y)#=8oci
aW@J]slg
import java.io.*; " UxKG+
import java.net.*; M;zJ1
z2Kvp"-}
0VwmV_6'<W
public class FileSplitterFetch extends Thread { ;1Zz-@
7@l.ZECJ1
!a<}Mpeg
String sURL; //File URL |"o/GUI~
long nStartPos; //File Snippet Start Position Ld$e -dB
long nEndPos; //File Snippet End Position o%V%@q H
int nThreadID; //Thread's ID $ITh)#Nj
boolean bDownOver = false; //Downing is over HqKI|^
boolean bStop = false; //Stop identical *7:HO{P>Y
FileAccessI fileAccessI = null; //File Access interface j/*4Wj[
jO+#$=C
wTK>U`o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {((|IvP`
{ t?6_^ 08
this.sURL = sURL; a?5R;I B
this.nStartPos = nStart; i.Jk(%c
this.nEndPos = nEnd; EL+P,q/b
nThreadID = id; 0DgEOW9H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?VP07 dQTe
} H;=++Dh
RY9h^q*
FNB4YZ6
public void run() aK4ZH}XHE"
{ ``9`Xq
while(nStartPos < nEndPos && !bStop) =BNS3W6
{ [7*$Sd
4E~!$Ustx
04wO9L;
try{ BkcA_a:W
URL url = new URL(sURL); \V/;i.ng
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); />[X k
httpConnection.setRequestProperty("User-Agent","NetFox"); YKWtsy
String sProperty = "bytes="+nStartPos+"-"; h:l4:{A64
httpConnection.setRequestProperty("RANGE",sProperty); |\iJ6m;a
Utility.log(sProperty); 3,4m|Z2)
fx`oe
BjsF5~+\
InputStream input = httpConnection.getInputStream(); jpI=B
//logResponseHead(httpConnection); jZLD^@AP
1Z| {3W
gW(7jFl
byte[] b = new byte[1024]; nD/; Gq
int nRead; (TQhO$,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C#Y_La
{ ]v6s](CE
nStartPos += fileAccessI.write(b,0,nRead); g?=|kp
//if(nThreadID == 1) %}x$YDO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =V(|3?N
} Wp0L!X=0
!w #x@6yq
\]gUX-
Utility.log("Thread " + nThreadID + " is over!"); wjnQK
bDownOver = true; LYvjqNC&4
//nPos = fileAccessI.write (b,0,nRead); !3 j@gi2
} pXBlTZf
catch(Exception e){e.printStackTrace ();} Z{gJm9
} p@Ng.HE
} f1}am<
6l|,J`G
;&8
//打印回应的头信息 i!k5P".o^
public void logResponseHead(HttpURLConnection con) O2 sAt3'
{ bQelU
for(int i=1;;i++) (iO8[
{ g (:%E
String header=con.getHeaderFieldKey(i); bL9EX$P
if(header!=null) ?!d\c(5Gt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0z1UF{{
Utility.log(header+" : "+con.getHeaderField(header)); k),!%6$
else N5Rda2m
break; :SD^?.W\iT
} 7B| #*IZe
} Fy'/8Yv#L
U#{^29ik=o
ZlxJY%oeu
public void splitterStop() ^:F |2
{ U9ZWSDs
bStop = true; yQ{xRtNO
} c4AkH|
qJ8@A}}8
13v#
} C%)Xz
c5f8pa *
1O{x9a5Z?O
/* 7ga|4j3%
**FileAccess.java *4<Kz{NF
*//文件访问(定位，写) _Boe"
package NetFox; Sy?O(BMo
import java.io.*; +_h1JE_}D
L dyTB@
!J@!P?0. C
public class FileAccessI implements Serializable{ alB[/.1
PpF"n[j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (g>>
RandomAccessFile oSavedFile; +>,4d
long nPos; bw\a\/Dw
eJv_`#R&Of
Q\ AM] U
public FileAccessI() throws IOException D3BNA]P\2@
{ f6d:5 X_
this("",0); n,+/%IZ
} `*`@ro
MsL*$*s
aOr'OeG(=e
public FileAccessI(String sName,long nPos) throws IOException F7r!zKXZ
{ 0M^v%22
oSavedFile = new RandomAccessFile(sName,"rw"); xct{Tv[FO
this.nPos = nPos; ?%Pd:~4D
oSavedFile.seek(nPos); lNw8eT~2
} D:yj#&I
/y.+N`_
(g8<"< N?
public synchronized int write(byte[] b,int nStart,int nLen) S3oSc<&2
{ (4WAoye|
int n = -1; 3TDjWW;#~
try{ r?l7_aBv3
oSavedFile.write(b,nStart,nLen); D0f.XWd
n = nLen; NWt`X!
} (6*CORE
catch(IOException e) .*bu:FuDE
{ r- :u*
e.printStackTrace (); 8LMO2Wyq
} uIO<6p)
}{(dG7G+
1oSrhUTy
return n; $%3"@$
} :s}6a23
v9t26>{~
[1\k'5rp
} !M&Qca2
PDEeb.(.
!&n'1gJ)kd
/* oJLpFL
**SiteInfoBean.java {vf"`#Q9
*/ R2 I 7d'|v
package NetFox; kX2bU$1Q,i
/2n-q_
S?M'JoYy
public class SiteInfoBean { C" W,
)Uk!;b
H:d@@/
private String sSiteURL; //Site's URL gC+PpY#2h
private String sFilePath; //Saved File's Path ?Bdhn{_
private String sFileName; //Saved File's Name !FqJP OGm
private int nSplitter; //Count of Splited Downloading File Pr%Y!|
bAsoIra
8-2e4^ g(
public SiteInfoBean() $@[`v0y*
{//nSplitter的缺省值为5 c89+}]mGq
//default value of nSplitter is 5 ds*N1[ *
this("","","",5); R.FC3<TTv
} }KBz8M5
`}Of'i
#c?xJ&bh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l. 9 i `
{ ;9+[t8Y)D
sSiteURL= sURL; lD%Fk3
sFilePath = sPath; !m* YPY31
sFileName = sName; w Bi'KS
this.nSplitter = nSpiltter; $hn=MOMc
j0XS12eM
Y M<8>d
} vH^6O:V
'K L"i
nI63Ns
public String getSSiteURL() N}j]S{j}'
{ -8r';zR
return sSiteURL; &7i o/d\/
} s?:&#
c,K)*HB
gyz#:z$p^
public void setSSiteURL(String value) Q(3Na6
{ %a_ rYrL
sSiteURL = value; w=ib@_:f
} bK\Mn95]
|[RoR
YPV@/n[N
public String getSFilePath() /Vg=+FEO
{ eNwF<0}
return sFilePath; ~6)A/]6
} x'4q`xDa
.d JX,^
GV+K] KDI
public void setSFilePath(String value) kgq"b)
{ y.O%
sFilePath = value; <?Z[X{
} \ r^#a
*[P"2b#
g[NmVY-o
public String getSFileName() 8zMt&5jD
{ +PlA#DZu
return sFileName; $:7T
} i1(}E#
mM[!g'*
X\-IAv
public void setSFileName(String value) _VjfH2Y
{ {CO]wqEj
sFileName = value; u["3| `C5
} R;G"LT
7z_EX8^
JJHfg)
public int getNSplitter() IzuYkl}
{ 8(6(,WwP}
return nSplitter; <WHu</
} A>?_\<Gp
j5rB+
Yq$KYB j
public void setNSplitter(int nCount) <r@w`G
{ xF#'+Y
nSplitter = nCount; H n^)Xw
} *&=sL
} ag_RKlM3
sbju3nvk
W<QMUu
/* q)m0n237P
**Utility.java hR g?H
*/ /:+f5\"-b
package NetFox; fLtN-w6t
j$<sq
Z7="on4
public class Utility { \Nvu[P
}MCh$
1(q&(p
public Utility() Z8Jrt3l{2
{ )wt mc4'
R7nT,7k.
'4"9f]:
} `X:o]t@
V,*<E&+
//线程睡眠 RZ6[+Ygn
public static void sleep(int nSecond) (uxe<'Co|
{ $ouw*|<
try{ |=o)|z2
Thread.sleep(nSecond); L&I8lG
} I*SrKZb
catch(Exception e) :rBPgrt
{ U5iyvU=UG
e.printStackTrace (); j_\?ampF
} MR?5p8S#g
} 5Al1u|;HB
N4xCZb
//日志 1@i|[dq
public static void log(String sMsg) `<"@&N^d
{ YUGEGXw
System.err.println(sMsg); H,{WrWA
} B%.vEk)*
G[bWjw86O
}%T8?d]
public static void log(int sMsg) C-}@.wr(
{ S{0iPdUC
System.err.println(sMsg); PX} ~
} nB &[R
} z>6hK:27
4GN
\Fs+H,S<
/* NKSK+ll2
**TestMethod.java ;UAi>//#
*/ Qvx[F:#Tk
package NetFox; P4VMGP
)Z"
zUIh^hbFf
public class TestMethod { [Zpx :r}
l!d |luqbA
&>xd6-
public TestMethod() (v)/h>vS
{ ///xx/weblogic60b2_win.exe DD?zbN0X
try{ }g9g]\.!a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }3TTtd7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $!ATj`}kb
SiteFileFetch fileFetch = new SiteFileFetch(bean); `xq/<U;i
fileFetch.start(); Fs3rsig
} -_KO}_
catch(Exception e){e.printStackTrace ();} 9'5`0$,|^
9*<=K
PsMp&~^
} 0DsW1
'Zket=Sm;
r3BQo[ 't
public static void main(String[] args) y"L7.B
{ hHsN(v
new TestMethod(); X1C &;5
} ]_EJ "'x
} \,ko'48@
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