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)); 9mv6
} )A;jBfr
for(int i=0;i<nEndPos.length-1;i++) +I~U8v-
{ DqH]FS?]
nEndPos = nStartPos[i+1]; a- /p/ I-%
} k"`^vV[{F
nEndPos[nEndPos.length-1] = nFileLength; 8/9YR(H3H
} n*=Tm KQ
} z\IZ5'
|R Qa.^.
/P{'nI
//启动子线程 6:TA8w|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SMm$4h R
for(int i=0;i<nStartPos.length;i++) `O,"mm^@U
{ oA ]F`N=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X0m6<q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7mS_Cz+cB
nStartPos,nEndPos,i); SQ`ec95',
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .V^h<d{
fileSplitterFetch.start(); ^6^A/]v
} "8yDqm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h3-dJgb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^W,x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3DrW[\
nEndPos = " + nFileLength); QtqE&j
// fileSplitterFetch[nPos.length-1].start(); 'P >h2^z
BG@[m
$-]PD`wmY
//等待子线程结束 771r(X?Fa
//int count = 0; v/C*?/ ~
//是否结束while循环 }D#[yE,=\
boolean breakWhile = false; 8F`799[p
U[l{cRT
& MfnH
while(!bStop) BO=j*.YKy
{ }2_i<4,L
write_nPos(); ^cYt4NHXn
Utility.sleep(500); :j!N7c{
breakWhile = true; ,HO@bCK
;!N_8{ 7r
!p"Ijz5
for(int i=0;i<nStartPos.length;i++) vJ!<7 l&
{ 0Z~G:$O/i
if(!fileSplitterFetch.bDownOver) 'WQ<|(:{
{ E@$HO_;&
breakWhile = false; fxk6q$'
break; lw 9rf4RF
} Dmv@ljwO
} AVv8Hhd
if(breakWhile) HTUY|^^D
break; ;F'/[l{+
c1Ta!p{%
L%O( I
//count++; N,NEg4 q[
//if(count>4) o8lwwM*
// siteStop(); !NFP=m1
} ,t_Fo-i7vI
Arb-,[kwN
q+-Bl
System.err.println("文件下载结束！"); m`lsUN,
} ^iq$zHbc0u
catch(Exception e){e.printStackTrace ();} i^'Uod0d.
} Fps.Fhm
%@Ty,d:;=
?]L:j
//获得文件长度 55T c
public long getFileSize() [m3k_;[
{ :X6A9jmd
int nFileLength = -1; _mw(~r8R
try{ KzC`*U[
URL url = new URL(siteInfoBean.getSSiteURL()); 5#U*vGVT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o!+jPwEU
httpConnection.setRequestProperty("User-Agent","NetFox"); Q@lJ|
#E( n
U0:tE>3`
int responseCode=httpConnection.getResponseCode(); yr /p3ys
if(responseCode>=400) }Myi0I<
{ j.@TPf*
processErrorCode(responseCode); 3%W R
return -2; //-2 represent access is error ~^Y(f'{
} ~\z\f}w
$fE$j {
4V`ypFme
String sHeader; .{1MM8 Q
>Cjb|f3'i}
G*|2qX"o
for(int i=1;;i++) vO)nqtw
{ f}'E|:Z 7k
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E30VKh |
//Utility.log(in.readLine()); ci^+T *
sHeader=httpConnection.getHeaderFieldKey(i); Tl!}9/Q5E:
if(sHeader!=null) 5[|MO.CB$
{ :B<lDcFKJ
if(sHeader.equals("Content-Length")) EK^ld!g(
{ 7 C5m#e3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K/y#hP
break; *HwTq[y
} ;!k1LfN
} @GYM4T
else B=/*8,u
break; yS#LT3>l
} [Uezi1I
} dOFxzk,g&R
catch(IOException e){e.printStackTrace ();} b "4W` A
catch(Exception e){e.printStackTrace ();} :/9@p
}XiS:
=J,aBp
Utility.log(nFileLength); _AQ :<0/#
FxC@KZG
)ll`F7B-
return nFileLength; e/WR\B'1
} /0 ,#c2aq
4b8!LzKS
bgd1j,PWbW
//保存下载信息（文件指针位置） Ftm%@S?
private void write_nPos() G1Cn[F;e
{ p3*}!ez4
try{ "6n~,$
output = new DataOutputStream(new FileOutputStream(tmpFile)); X+{4,?04+
output.writeInt(nStartPos.length); S*:b\{[f>
for(int i=0;i<nStartPos.length;i++) N`/6 By
{ nVoPTr
// output.writeLong(nPos); #5T+P8
output.writeLong(fileSplitterFetch.nStartPos); ]OHzE]Q
output.writeLong(fileSplitterFetch.nEndPos); D:llGdU#2
} vcAs!ls+
output.close(); `,&h!h((
} VuFH >8n
catch(IOException e){e.printStackTrace ();} U]fE(mpI9
catch(Exception e){e.printStackTrace ();} iwL\Ha
} jGEUl=W
l?B\TA^
V2%FWo|
//读取保存的下载信息（文件指针位置） g^1M]1.f
private void read_nPos() q[l},nw
{ KLs%{'[7:
try{ TC3xrE:U<m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (hVhzw"~
int nCount = input.readInt(); G;FY2;adK
nStartPos = new long[nCount]; V$-IRdb
nEndPos = new long[nCount]; y&A*/J4P
for(int i=0;i<nStartPos.length;i++) 0W9,uC2:N
{ 5>q|c`&}E
nStartPos = input.readLong(); R1X9
nEndPos = input.readLong(); _I~W!8&w>
} m"~$JA u
input.close(); @Wy>4B^
} yuk64o2QE
catch(IOException e){e.printStackTrace ();} vj^vzFbK
catch(Exception e){e.printStackTrace ();} d)(61
} r<Ll>R
8MM#q+8
y_38;8ex
private void processErrorCode(int nErrorCode) x9~d_>'A
{ 7Rk eV
System.err.println("Error Code : " + nErrorCode); yEy} PCJ&
} #~q{6()e:
oKiBnj5J
Ezm ~SY
//停止文件下载 <Jo_f&&{
public void siteStop() ' V;cA$ $
{ q/?#+d
bStop = true; \QstcsEt
for(int i=0;i<nStartPos.length;i++) rcPP-+XW
fileSplitterFetch.splitterStop(); a{QHv0goG
^/2n[orl5
fEWS3`Yy
} vN-#Ej. u
} y|nMCkuX
//负责部分文件的抓取 ^{_`jE
**FileSplitterFetch.java s$:F^sxb
*/ u}JL*}Q
package NetFox; L=Fm:O'#2
T#Qn\8
0~H(GG$VH
import java.io.*; #q%xJ[
import java.net.*; &p^S6h
]ZelB,7q
B8'" ^a^&-
public class FileSplitterFetch extends Thread { ^UZEdR;
+iir]"8
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String sURL; //File URL [7ZFxr\:!
long nStartPos; //File Snippet Start Position bg*4Z?[dd
long nEndPos; //File Snippet End Position E#`=xg
int nThreadID; //Thread's ID 07DpvhDQ
boolean bDownOver = false; //Downing is over G@oY2sM"
boolean bStop = false; //Stop identical 4iBp!k7
FileAccessI fileAccessI = null; //File Access interface =M>1;Qr<Z/
+#}I^N
j#"?Oe{_1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 13I 7ah
{ PCH&eTKN
this.sURL = sURL; ``)ys^V
this.nStartPos = nStart; L@2T
this.nEndPos = nEnd; b-'41d}Hn
nThreadID = id; xI55pj*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4*g`!~)
} b{=2#J-
rJ4O_a5/
x'{L%c>L
public void run() YQvN;W
{ t>.mB@se|
while(nStartPos < nEndPos && !bStop) ~&4Hc%*IB
{ +N:K V}K
)d!,,o
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try{ QM=M<~<Voh
URL url = new URL(sURL); 4pq@o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); acz8 H0cS
httpConnection.setRequestProperty("User-Agent","NetFox"); )Ge.1B$8h
String sProperty = "bytes="+nStartPos+"-"; dFFJw[$8w
httpConnection.setRequestProperty("RANGE",sProperty); Q"n*`#Yt'
Utility.log(sProperty); MU4/arXy
s9>f5u?dK
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InputStream input = httpConnection.getInputStream(); @cA`del
//logResponseHead(httpConnection); uIvy1h9m
+!6aB|-
m_\w)
byte[] b = new byte[1024]; S#Tc{@e
int nRead; T$5u+4>"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i\lur ET
{ uo;aC$US
nStartPos += fileAccessI.write(b,0,nRead); 3e~ab#/
//if(nThreadID == 1) U~n>k<`sr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?Y7'OlO
} _fx0-S*$
'^)Ve:K-.
")'o5V
Utility.log("Thread " + nThreadID + " is over!"); YjN2 ,Xi
bDownOver = true; WeNx9+2=Z
//nPos = fileAccessI.write (b,0,nRead); dqMt6b\}
} +e?mKLw14
catch(Exception e){e.printStackTrace ();} y|f`sBMM
} ~G|un}g=
} 3^AycwNBA
.}n,
,e{(r0
//打印回应的头信息 /` 891(f,
public void logResponseHead(HttpURLConnection con) -\6nT'P
{ z/6/
for(int i=1;;i++) Vw.c05x
{ =r=[e}&9
String header=con.getHeaderFieldKey(i); q"xIW0Pc
if(header!=null) hfT HP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _Mq0QQ42
Utility.log(header+" : "+con.getHeaderField(header)); qplz !=
else ]H<5]({F
break; )';Rb$<Qn
} >Pne@w!*
} wv0d"PKTS
k~f3~-"
,_;+H*H>"
public void splitterStop() os6p1"_\f
{ d\Cx(Lb[
bStop = true; CBw/a0Uck
} np3$bqm
4|*b{Ni
w:xLg.Eq6
} >^}nk04
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q] g'rO'
/* *#+e_)d
**FileAccess.java E +\?|q !T
*//文件访问(定位，写) AffVah2o:
package NetFox; EQZu-S`kv
import java.io.*; .3WDtVE
@8WG
9Fb|B
public class FileAccessI implements Serializable{ ^.bYLF
5sJi- ^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .w5#V|
RandomAccessFile oSavedFile; lrSdFJ%
long nPos; %-ih$ZY
vlYDhjZk#
;%"YA
public FileAccessI() throws IOException t}m6];
{ w5*?P4P
this("",0); #hL<9j
} P|}~=2J
DVCO( fz
|jB]5ciT
public FileAccessI(String sName,long nPos) throws IOException p&1IK8i"
{ `:WVp~fn
oSavedFile = new RandomAccessFile(sName,"rw"); _4qP0LCa
this.nPos = nPos; g7*cwu
oSavedFile.seek(nPos); j" wX7
} .5=Qfvi*
J }izTI
mq~rD)T
public synchronized int write(byte[] b,int nStart,int nLen) :$Lu V5
{ }'HJVB_
int n = -1; 0l#{7^e
try{ d"zbY\`
oSavedFile.write(b,nStart,nLen); <3\t J
n = nLen; ca>6r`
} RFF&-M]
catch(IOException e) 7{=<_
{ ow:}NI
e.printStackTrace (); |~mq+:44+
} KQsS)ju
".+wz1
$<^4G
return n; `q Sfo`
} I}oxwc
F 7+Gt Ed
.<JD'%?"
} arf`%9M
S-[]z*
12)~PIaF
/* dR2#n
**SiteInfoBean.java 2!QS&i
*/ l'YpSO~l7
package NetFox; [~$Ji&Dd
S!gV\gEbDj
]>h2h?2te
public class SiteInfoBean { CL/8p;
uiq)?XUKv
@]lKQZ^2&
private String sSiteURL; //Site's URL Te?UQX7Z}M
private String sFilePath; //Saved File's Path /$zYSP)YT
private String sFileName; //Saved File's Name \ ?['pB
private int nSplitter; //Count of Splited Downloading File (n7v $A
e#`wshtN:
}x% ;y]S
public SiteInfoBean() 061@N=p8
{//nSplitter的缺省值为5 ,ZjbbBZ
//default value of nSplitter is 5 V.J[Uwf
this("","","",5); ^!^8]u<Q
} q[]EVs0$ew
bG nBV7b
$5nOiaQL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ni IX^&N1
{ w#_xV =
sSiteURL= sURL; }8 A]
sFilePath = sPath; "PGEiLY
sFileName = sName; cT^,[3i:c
this.nSplitter = nSpiltter; ]t_AXKd
J'tc5Ip!}V
*{:FPmDU
} Uj}iMw,
w#k'RuOw5
Dw
public String getSSiteURL() cF_`m
{ <jU[&~p
return sSiteURL; 3EB8ls2
} ~=(?Z2UDA_
C)`ZI8
->&AJI0
public void setSSiteURL(String value) pgT{#[=>
{ %YefTk8cr,
sSiteURL = value; =3lUr<Ze
} {c|nIwdB
Ac<V!v71
":?>6'*1
public String getSFilePath() )K>XLaG)
{ "v4;m\g&:
return sFilePath; a^i`DrX
} yd5r]6ej
laqKP+G
a9Lf_/w{&
public void setSFilePath(String value) |//cA2@.
{ V| z|H$-
sFilePath = value; 9a2Ga
} *ghkw9/
cqr!*
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public String getSFileName() Y&`Vs(
{ hFuS>Hx
return sFileName; %yJL-6U
} wA) NB
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^CI.F.#X|
public void setSFileName(String value) u*{hXR-"
{ #*#4vMk<
sFileName = value; E*>tFw&[
} o+`W
lYT}Nc4"="
=1)yI>2e%}
public int getNSplitter() %m!o#y(hD`
{ k=H{gt
return nSplitter; i;*c|ma1>
} I>bLgt]u3
b*qkox;j
jJ?MT#v
public void setNSplitter(int nCount) ~el#pf~
{ p9XHYf72
nSplitter = nCount; !tv3.:eT
} 3X*;.'#Z
} 's@v'u3
IK(G%dDw
,ZV<o!\
/* F*>:~'%
**Utility.java y.JAtsxD
*/ < Upn~tH
package NetFox; >k*QkIyq
B~-VGT2o
>pO[S[
public class Utility { ~xGWL%og
IE: x&q`3
c%>t(ce`Tl
public Utility() s2_j@k?%
{ ,f0cy\.?
7on$}=%
MG[?C2KA/
} idvEE6I@
'SYjEhvw
//线程睡眠 y&t&'l/m
public static void sleep(int nSecond) jr~ +}|@{
{ 4?><x[l2{
try{ y1cAw
Thread.sleep(nSecond); u3Z*hs)Z%
} [WXtR
catch(Exception e) ,[,+ _A
{ {3yzC
e.printStackTrace (); v+znKpE
} -5>K pgXo\
} 50rCW)[#
5b0Ipg
//日志 D@^ r
public static void log(String sMsg) |iLeOztuE
{ -9}]J\
System.err.println(sMsg); ]n${j/x
} |q^e&M<
?T7`E q
a^iefwsNc
public static void log(int sMsg) PQWo<Uet
{ 3lMmSKN
System.err.println(sMsg); J^hj R%H
} =:P9 $
} ZL#4X*zT
h#^IT
%N|7<n<S
/* `XP]y=
**TestMethod.java $7jJV(B
*/ bnWIB+%_
package NetFox; )+RGXVp
2[[pd&MJZ
{O5;V/00}
public class TestMethod { k <A>J-|
zbddn4bW9
3xsC"c>
public TestMethod() <6mXlK3N0
{ ///xx/weblogic60b2_win.exe R5X<8(4p
try{ !a[ voUS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &1F)/$,v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -1Lh="US
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8 fVI33
fileFetch.start(); N1\u~%AT"
} UN`-;!
catch(Exception e){e.printStackTrace ();} r444s8Y
l|%7)2TyG)
o83HR[
} M)Yu^
}z,4IHNn
"#rlL^9v
public static void main(String[] args) b}9K"GT
{ U/&?rY^|
new TestMethod(); A_{QY&%m
} rD%(*|Y"c
} Al$"k[-Uin
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