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)); i hcSSUm
} `_e5pW=:>
for(int i=0;i<nEndPos.length-1;i++) 2$b JMx>
{ }poLHS/
nEndPos = nStartPos[i+1]; #_Z)2ESX
} 8Om4G]*|,
nEndPos[nEndPos.length-1] = nFileLength; XwIhD
} %^l&:\ hy
} R>hL.+l.
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}8[
//启动子线程 /^$n&gI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PQ2rNY6
for(int i=0;i<nStartPos.length;i++) v;#0h7qd
{ bFVY&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qRL45[ K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MIY`"h0*
nStartPos,nEndPos,i); -oi@1g@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,z~"Mst
fileSplitterFetch.start(); =g|5VXW5
} !NMiWG4R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D< 0))r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); umN4|X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V;"Rp-`^
nEndPos = " + nFileLength); -`D<OSt7
// fileSplitterFetch[nPos.length-1].start(); gI00@p:m
9^E!2CJ
^qLesP#
//等待子线程结束 w\a6ga!xt"
//int count = 0; S59^$
//是否结束while循环 tA^CuJR
boolean breakWhile = false; l[^0Ik-G
0:$pJtx"
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while(!bStop) xy]oj
{ r-No\u_
write_nPos(); piFZu/~Gq\
Utility.sleep(500); 8WpZ"
breakWhile = true; Ec&_&
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Y+eDE:4
for(int i=0;i<nStartPos.length;i++) 0nZQ"{x
{ [U:P&)
if(!fileSplitterFetch.bDownOver) <Qt9MO`a
{ [8&+4<
breakWhile = false; Y*sw;2Z;a
break; u7
} :Sn4Pg `Q
} Q]<6voyy
if(breakWhile) @U:PXCvh
break; |CAMdU
vXg^K}a#
_<'?s>(U'
//count++; T1%}H3
//if(count>4) +v/-qyA
// siteStop(); ^O!;KIe{g
} TLq^5,qG
Js^(mRv=
Zr(eH2}0D
System.err.println("文件下载结束！"); eQ*zi9na
} "q KVGd
catch(Exception e){e.printStackTrace ();} rDGrq9
} @sUec
v6ei47-
n<1*cL:8B
//获得文件长度 D^6Q`o
public long getFileSize() jp|*kBDq\
{ 4I#@xm8)
int nFileLength = -1; h]/3doP
try{ gAgF$H .
URL url = new URL(siteInfoBean.getSSiteURL()); E=91k.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \Nk578+AA
httpConnection.setRequestProperty("User-Agent","NetFox"); sQ+s3x1y
)4N1EuD6
]|u7P{Z"R
int responseCode=httpConnection.getResponseCode(); X^rFRk
if(responseCode>=400) 53>(2 _/[r
{ <d O~;
processErrorCode(responseCode); 1jE {]/Y7&
return -2; //-2 represent access is error y;_F[m
} 5s@xpWVot
WWC&-Ni
!w%p Gv.wg
String sHeader; x~F YG
7a=ul:
O:ACp<@
for(int i=1;;i++) ">MsV/
{ G cB<i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Zu4au<
//Utility.log(in.readLine()); J:OP*/@='
sHeader=httpConnection.getHeaderFieldKey(i); 0sH~H[ap
if(sHeader!=null) smn~p/u
{ >!%+9@a}
if(sHeader.equals("Content-Length")) 6n~)R
{ Q(O0z3b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Tp.:2[
break; )l.AsfW%
} ia,5=SKJ
} O8Z+g{
else D5:|CMQ
break; H?,Dv>.#*
} 14A(ZWwq9
} ,/kZt!
catch(IOException e){e.printStackTrace ();} g~U<0+&yw%
catch(Exception e){e.printStackTrace ();} KpDb%j
Qg0%rbE
(" +clb`
Utility.log(nFileLength); =uEpeL~d;+
2vhP'?;K
bjI3xAs~
return nFileLength; ?H>^X)Ph
} &[SFl{fx>-
brG!TJ
KzQFG)q,
//保存下载信息（文件指针位置） y:_>R=sw
private void write_nPos() u6%\ZK._ \
{ )&Z`SaoP|J
try{ I8c:U2D
output = new DataOutputStream(new FileOutputStream(tmpFile)); X&i;WI
output.writeInt(nStartPos.length); PjXiYc&
for(int i=0;i<nStartPos.length;i++) OUFy=5(%:
{ 5z\,]
// output.writeLong(nPos); F_I!qcEQ
output.writeLong(fileSplitterFetch.nStartPos); \<dg
output.writeLong(fileSplitterFetch.nEndPos); ?uU_N$x
} $zF%F.rln
output.close(); l]j;0i
} ]{|lGtK %
catch(IOException e){e.printStackTrace ();} Q [C26U
catch(Exception e){e.printStackTrace ();} #,97 ]
} |'I>Ojm
KW3<5+w]c
<L<^uFB
//读取保存的下载信息（文件指针位置） O#p_rfQ
private void read_nPos() 9XKqsvdS
{ Ep:hObWG)
try{ %I{>H%CjE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6J@,bB jVz
int nCount = input.readInt(); C%{2 sMJz
nStartPos = new long[nCount]; 78 ]Kv^l^_
nEndPos = new long[nCount]; 'X6Z:dZY
for(int i=0;i<nStartPos.length;i++) g4YlG"O[~
{ !aKu9SR^e
nStartPos = input.readLong(); 2-jXj9kp`
nEndPos = input.readLong(); f~/hsp~Hp
} 7WY~v2SDF
input.close(); 1Kr$JIcd
} s:_a.4&Y
catch(IOException e){e.printStackTrace ();} wwQ2\2w>Hm
catch(Exception e){e.printStackTrace ();} NHe)$%a=H
} vVIND
J*Ie# :J]
+6$-"lf
private void processErrorCode(int nErrorCode) (:O6sTx-hE
{ <&gs)BY
System.err.println("Error Code : " + nErrorCode); T>7N "C
} "6U@e0ht
<QC7HR
uPapINj
//停止文件下载 &:u3-:$:9
public void siteStop() #I*{_|}=
{ M d8(P23hS
bStop = true; sC.r$K+k5
for(int i=0;i<nStartPos.length;i++) `9gV8u
fileSplitterFetch.splitterStop(); 4:^MSgra
pLCS\AUTsv
!]E]Xd<
} $ZZ?*I
} K=E+QvSG
//负责部分文件的抓取 gat;Er
**FileSplitterFetch.java 5j$&Zgx51
*/ r!O[|h
package NetFox; BFhEDkk
nB5\ocJ
\13Q>iAu
import java.io.*; *3!r &iY
import java.net.*; *9xxX,QT8Q
<2L,+
q5JQx**g
public class FileSplitterFetch extends Thread { fA]sPh4Uag
Q672iR\#)
"I:*
String sURL; //File URL ^IyQzBOj
long nStartPos; //File Snippet Start Position .'Q*_};W
long nEndPos; //File Snippet End Position I8% -ii
int nThreadID; //Thread's ID WTM
boolean bDownOver = false; //Downing is over Pk;yn;
boolean bStop = false; //Stop identical 7U1M;@y
FileAccessI fileAccessI = null; //File Access interface ,4`Vl<6
Ea][:3
g/ShC8@=u
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9nY|S{L
{ J~4mp\4b
this.sURL = sURL; rx 74v!
this.nStartPos = nStart; 9S[.ESI{>
this.nEndPos = nEnd; kB=B?V~#
nThreadID = id; {dh,sbl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H&%oHyK
} TwVkI<e0s?
e`H>}O/ai
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public void run() 0Zp5y@V8
{ US3)+6
while(nStartPos < nEndPos && !bStop) rXT?w]4
{ y N9~/g
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::'Y07
try{ ~piE$"]&
URL url = new URL(sURL); HeO&p@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =nc;~u|]
httpConnection.setRequestProperty("User-Agent","NetFox"); M!mw6';k
String sProperty = "bytes="+nStartPos+"-"; K(lSR
httpConnection.setRequestProperty("RANGE",sProperty); OcPgw/ I
Utility.log(sProperty); AXte&l=M
bZ:+q1 D
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InputStream input = httpConnection.getInputStream(); cYe2a"
//logResponseHead(httpConnection); u-s*k*VHoc
]!P8{xmb@
S]|sKY
byte[] b = new byte[1024]; rc<Ix
int nRead; V|B4lGS&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 64mD%URT
{ OIpT9
nStartPos += fileAccessI.write(b,0,nRead); \'[tfSB
//if(nThreadID == 1) Ii5U)"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [7HBn
} 1 I.P7_/
~Ey+
Wa.xm_4s2
Utility.log("Thread " + nThreadID + " is over!"); 8Dtpb7\o
bDownOver = true; 53ZbtEwhwr
//nPos = fileAccessI.write (b,0,nRead); <82&F
} e1E_$oJP
catch(Exception e){e.printStackTrace ();} oQ/T5cOj
} oIx|)[
} (~{Y}n]s
94dd )/a
6| o S 5
//打印回应的头信息 v<g~EjzCf
public void logResponseHead(HttpURLConnection con) febn?|@
{ u/S>*E
for(int i=1;;i++) w xte
{ 7B\NP`l
String header=con.getHeaderFieldKey(i); 0gW{6BtPWm
if(header!=null) 3h>L0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (`E`xb@E,=
Utility.log(header+" : "+con.getHeaderField(header)); %,z;W-#gnY
else 4%8den,|
break; ?E+f<jol
} u kZK*Y9P
} CadIux^
%xG<hNw/
nh5=0{va|L
public void splitterStop() _izjvg
{ g]}!
bStop = true; bHx@
} tJ6Q7 J;n
~8mz.ZdY
hgW1g#
} ^,^MW
uM_ww6
TIl 'Z7
/* 4@Db $PHs
**FileAccess.java U*\K<fw
*//文件访问(定位，写) l4r>#n\yj
package NetFox; s$fX ;
import java.io.*; Ai[@2AyU
SpU|Q1Q/h
:Z2997@Y
public class FileAccessI implements Serializable{ @#N7M2/
PWx%~U.8~j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @MTv4eC}e
RandomAccessFile oSavedFile; @~|;/OY>"
long nPos; X])iQyN
Nb !i_@m%s
U?{oxy_[2
public FileAccessI() throws IOException Wu|MNB?M
{ o8<~zeI
this("",0); KN657 |f
} 'NCqI
Gds(.]_
[?9 `x-Q
public FileAccessI(String sName,long nPos) throws IOException %dW;P[0
{ umq6X8K
oSavedFile = new RandomAccessFile(sName,"rw"); T*0;3&sA
this.nPos = nPos; f -F}~S
oSavedFile.seek(nPos); b/R7Mk1
} o/VT"cT
Z:N;>.3i
*w _o8!3-
public synchronized int write(byte[] b,int nStart,int nLen) 5XHejHn>
{ 6.KEe^[-
int n = -1; ] L#c <0
try{ Jh&DL8`
oSavedFile.write(b,nStart,nLen); M@h"FuX:
n = nLen; :n{{\SSIgX
} D^m2iW;
catch(IOException e) 0?/gEr
{ ^zO{Aks
e.printStackTrace (); XLaD#J
} U_PH#e
i6n,N)%H
F09%f"9
return n; "h[)5V{
} fvH{va.
%(khE-SW
fw,,cu`YA
} m{RXt
nM.g8d K
d ([~o
/* yc3/5]E&
**SiteInfoBean.java &}P#<"Fo8Q
*/ vw3[(_MV3_
package NetFox; [fT$# '6
uyk;]EYjHZ
y3 N[F
public class SiteInfoBean { gU|:Y&lFZg
xcmg3:s
\rxjvV4fcZ
private String sSiteURL; //Site's URL :X'B K4EN
private String sFilePath; //Saved File's Path [[<TW}
private String sFileName; //Saved File's Name uQdy
private int nSplitter; //Count of Splited Downloading File =gJ{75tV3
D>W&#A8&y
fUWrR1
public SiteInfoBean() JmR2skoV,
{//nSplitter的缺省值为5 >I~Q[
//default value of nSplitter is 5 =Jw*T[E
this("","","",5); Fs4shrt
} |3B<;/v5
7~Inxk;
W =Bw*o-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l\V1c90m
{ 'R-\6;3E>9
sSiteURL= sURL; -o"b$[sf=Z
sFilePath = sPath; WUz69o be
sFileName = sName; NnHaHX
this.nSplitter = nSpiltter; aBaiXv/*
}F.k,2
L(Twclrb
} {vW0O&[
LFi* O&
;DnUeE8
public String getSSiteURL() vI(LIfe;
{ }2RbX,0l9
return sSiteURL; E+XS7':I
} LB]3-FsU+
K O\HH
+l)t5Mg\
public void setSSiteURL(String value) c\rP -"C
{ }UGSE2^1
sSiteURL = value; )Z/w|5<
} P nE7}
9{A4>
*?1\S^7R
public String getSFilePath() Tb2#y]27
{ psIo[.$rTk
return sFilePath; j96}E/gF
} IZ>l
}qp)VF
H6K8.
public void setSFilePath(String value) mUP!jTF
{ ju[y-am$/
sFilePath = value; 'JdK0w#
} rWNe&gFM
L#a!fd
)O+Zbn
public String getSFileName() R|)l^~x
{ ZoJqJWsd
return sFileName; %$o[,13=
} = )3\B
s92ol0`
nPI$<yW7F
public void setSFileName(String value) N3#^Ifn[
{ 3D@3jyo:
sFileName = value; }[!=O+gO
} zTMLE~w
;Q vQ fV4
q#8\BOTP |
public int getNSplitter() L|#0CRiN
{ zq$L[X
return nSplitter; +\ "NPK@3
} O[U`(A:
@.k^ 8hc
M'R ] ''
public void setNSplitter(int nCount) ~QUNR?h
{ 4*f+np
nSplitter = nCount; >JA-G@3i
} |LLpG37_
} |dHtv6I
9wf"5c
ZZHQ?p-
/* v\G7V
**Utility.java `q^qe>'
*/ k_u!E3{~
package NetFox; 7uw-1F5x7
Z6Mjc/
W)f=\.7
public class Utility { vmNI$KZM
&J9 + 5L8
32aI0CT
public Utility() Xe:^<$z
{ !9r%d8!z
H2[0@|<<
0>-}c>
} t~ I;IB
St!0MdCH
//线程睡眠 K@[Hej6d
public static void sleep(int nSecond) P$y'``
{ q4!\^HwQ
try{ vY.VFEP/
Thread.sleep(nSecond); dJrUcZBr
} $E;Tj|W
catch(Exception e) ydY(*]
{ rrgOp5aV"
e.printStackTrace (); nLk`W"irM
} 6/g 82kqpk
} /L(}VJg-
+]wM$bP
//日志 =Sr<d|\O
public static void log(String sMsg) ]FvGAG.*
{ "B+F6
System.err.println(sMsg); Pz D30VA
} QAo/d4
u~FVI
Oop6o$k
public static void log(int sMsg) wmR~e
{ ^@=4HtA
System.err.println(sMsg); Fo;J3<U)
} yoe@]c=
} =5^1Bl
2-UD^;0
$g VbeQ
/* >;j&]]-&
**TestMethod.java W79.Nj2`
*/ |${ImP
package NetFox; :6(@P1vA 6
yXEI%2~)
UYy #DA
public class TestMethod { {=J:
}C["'tLX
EAWBgOO8iC
public TestMethod() %}~(%@qB>+
{ ///xx/weblogic60b2_win.exe @}PX:*c
try{ Vz-q7*o$S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pih 0ME}z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r.Z g<T
SiteFileFetch fileFetch = new SiteFileFetch(bean); e9Gu`$K
fileFetch.start(); vy={ziJ
} "u$XEA
catch(Exception e){e.printStackTrace ();} /D|q-`*K
s]A8C^;c
[%6)
} xf7YIhL^*
7l*vmF6Z
U6H3T0#
public static void main(String[] args) a\,V>}e
{ NZ8X@|N
new TestMethod(); Tz9 (</y
} j}tGcFwvSN
} ofz?L#:2
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