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)); ss'`[QhR2
} js F96X{
for(int i=0;i<nEndPos.length-1;i++) &XZS}n
{ bR}=bp4K
nEndPos = nStartPos[i+1]; f0ME$:2
} VQ/Jz5^
nEndPos[nEndPos.length-1] = nFileLength; LWIPq"
} `kM:5f+>W
} dPb@[k
~9JLqN"
HOb0\X
//启动子线程 %y[ t+)!E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ByivV2qd{
for(int i=0;i<nStartPos.length;i++) ~@ML>z7
{ 'eg;)e:`b+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w;]~2$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2>'/!/+R
nStartPos,nEndPos,i); p -wEPC0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BkJNu_{m?
fileSplitterFetch.start(); 0Q5fX}
} {Ax{N
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;To][J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XHYVcwmDz-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 57rH`UFXH
nEndPos = " + nFileLength); ]}A3Pm- t*
// fileSplitterFetch[nPos.length-1].start(); ES9|eo6
'Ej&zh
TW!>~|U)y
//等待子线程结束 wJ>2}
//int count = 0; Hmv@7$9s\
//是否结束while循环 ~]C m
boolean breakWhile = false; qV7nF }V{
H-'~c\)
@ZtDjxN &
while(!bStop) #n6<jF1G
{ ]`u_d}`
write_nPos(); #9u2LK
Utility.sleep(500); !fK9YW(Im
breakWhile = true; :uQ~?amM
MtXTh*4
+@jX|
for(int i=0;i<nStartPos.length;i++) sY@x(qkIOc
{ b5Vn_;V*
if(!fileSplitterFetch.bDownOver) ;6/dFOZn
{ D>m!R[!o
breakWhile = false; \Ss6F]K]
break; i5CBLv
} f) @-X!
} ^gd[UC-"w
if(breakWhile) 2Pic4Z
break; Mhiz{Td
~-zch=+u
V^E.9fs,
//count++; wC>Xu.Z:
//if(count>4) HRF;qR9v
// siteStop(); Hribk[99
} s2;b-0
vY'E+M"+@
qgk6 \&K[
System.err.println("文件下载结束！"); |nq}#
} V>:ubl8j0l
catch(Exception e){e.printStackTrace ();} -Gn0TA2/C
} mrId`<L5l{
6ujePi <U
#P5tTCM
//获得文件长度 ^E= w3g&
public long getFileSize() JsyLWv@6xa
{ (|_N2R!
int nFileLength = -1; }RN&w]<
try{ uwhb-.w
URL url = new URL(siteInfoBean.getSSiteURL()); :Miri_l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9Netnzv%
httpConnection.setRequestProperty("User-Agent","NetFox"); @-G^Jm9~\m
.7v .DR>
PA<<{\dp
int responseCode=httpConnection.getResponseCode(); zpM%L:S
if(responseCode>=400) _7Rp.)[&
{ t182&gpd`
processErrorCode(responseCode); C3z#A3&J
return -2; //-2 represent access is error zcE[wM
} w;4FN'
\'.#of
e9@7GaL`"S
String sHeader; 8nQjD<-
bj`mQMC
3gNVnmZG
for(int i=1;;i++) N;.}g*_+}
{ i{5,mS&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r'~^BLT`#
//Utility.log(in.readLine()); Kt\#|-{CH-
sHeader=httpConnection.getHeaderFieldKey(i); ~.L\f%<
if(sHeader!=null) WC *e#QP
{ \g<=n&S?
if(sHeader.equals("Content-Length")) W*/0[|n*
{ J8:f9a:|M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xIb^x=|h
break; zf}X%tp
} W&Pp5KR
} ,sln0
else <Zn-P
break; Qkq9oZ
} 568qdD`PS
} 2c4x=%
catch(IOException e){e.printStackTrace ();} mZ^ev;
catch(Exception e){e.printStackTrace ();} WZ]f \S
dzn[4
C=uYX"
Utility.log(nFileLength); UthH
'I8K1Q=/
\.,qAc\[
return nFileLength; '&n4W7
} ^;=L|{Xl
Ln C5"
w!N?:}P<N
//保存下载信息（文件指针位置） F,'rW:{HMt
private void write_nPos() M9scZuj
{ ERQc1G]3Dd
try{ mf\eg`'4?
output = new DataOutputStream(new FileOutputStream(tmpFile)); GfMCHs
output.writeInt(nStartPos.length); H(WRm1i"G
for(int i=0;i<nStartPos.length;i++) daakawn+
{ TE!+G\@
// output.writeLong(nPos); PGaYYc3X
output.writeLong(fileSplitterFetch.nStartPos); g7r_jj%ow
output.writeLong(fileSplitterFetch.nEndPos); : ZWKrnG
} cTQ]0<9:e
output.close(); \WN,.
} y+g01z
catch(IOException e){e.printStackTrace ();} QFYO_$1Y)
catch(Exception e){e.printStackTrace ();} F#^<t$5t
} 1YxG<K]
{} gr\
"x P2GZ
//读取保存的下载信息（文件指针位置） wSwDhOX=
private void read_nPos() YN>k5\M_v
{ MrGq{,6C
try{ -=)Al^V4T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @;K-@*k3
int nCount = input.readInt(); h.ln%6:d
nStartPos = new long[nCount]; U81--'@y
nEndPos = new long[nCount]; r(Vz(
for(int i=0;i<nStartPos.length;i++) m}oqs0xx
{ GZ@`}7b}
nStartPos = input.readLong(); A;\1`_i0
nEndPos = input.readLong(); W-UMX',0zS
} IVblSiFF
input.close(); -4IHs=`;I
} /suW{8A(E
catch(IOException e){e.printStackTrace ();} 2S^:fm}
catch(Exception e){e.printStackTrace ();} rrL gBeQa
} Un[ 0or
9KgGK cy%
Gi=s|vt
private void processErrorCode(int nErrorCode) Jv+N/+M47
{ yy*8Aw}
System.err.println("Error Code : " + nErrorCode); jFr[T
} d%wy@h
bh&Wy<Y
fKYRDGn
//停止文件下载 _b)=ERBbCo
public void siteStop() O7of9F~"
{ {#o0vWS>
bStop = true; RL|d-A+;
for(int i=0;i<nStartPos.length;i++) do$+ Eh
fileSplitterFetch.splitterStop(); a?dUJt
]QbT%0
fC7rs5
} 4 [K"e{W3
} 'Jl |-RUd
//负责部分文件的抓取 <jwQ&fm)/R
**FileSplitterFetch.java "7X[@xX@
*/ {k"t`uo_
package NetFox; 9>I&Z8J$M
(O@fgBM
<Mq vGXI
import java.io.*; 2^;zj0]Rt
import java.net.*; DY(pU/q
h%*@82DKK
3)6&)7`*
public class FileSplitterFetch extends Thread { G3wkqd
}8e_
9z9\pXFQ
String sURL; //File URL N R0"yJV>
long nStartPos; //File Snippet Start Position i] I{7k
long nEndPos; //File Snippet End Position }gR!]Cs)^
int nThreadID; //Thread's ID !CGpE=V
boolean bDownOver = false; //Downing is over `:>N.9'o
boolean bStop = false; //Stop identical A6Vb'Gqv{
FileAccessI fileAccessI = null; //File Access interface S8Ec.]T
9(AY7]6
`$oy4lDKQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p`I[3/$3
{ ^1mnw@04
this.sURL = sURL; N}\%r&KR=
this.nStartPos = nStart; 5"WI^"6b:
this.nEndPos = nEnd; f]C`]qg
nThreadID = id; @yj$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,%X"Caz
} LuE0Hb"S8
9 7Ua,
qe<xH#6
public void run() >.o<}!FW
{ &rbkw<=j
while(nStartPos < nEndPos && !bStop) %5yP^BL0
{ ;ZtN9l
j' }4ZwEh
4Wk`P]?^
try{ #9e2+5s
URL url = new URL(sURL); /:.p{y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r"&uW!~0
httpConnection.setRequestProperty("User-Agent","NetFox"); b'1m 9T780
String sProperty = "bytes="+nStartPos+"-"; #6F|}E
httpConnection.setRequestProperty("RANGE",sProperty); 8c3/n
Utility.log(sProperty); N#<X"&-_#
o5;|14O
O/b1^ Y
InputStream input = httpConnection.getInputStream(); ?[#4WH-G
//logResponseHead(httpConnection); Memb`3
\f-@L;8#
<Eu/f`8
byte[] b = new byte[1024]; uGU-MC*
int nRead; >v'@p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j^)=<+Q;=
{ %$6?em_
nStartPos += fileAccessI.write(b,0,nRead); u/.# zn@9h
//if(nThreadID == 1) +k{l]-)1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ov~vK\
} "UUoT
&ev#C%Nu
CsX@u#
Utility.log("Thread " + nThreadID + " is over!"); @QfbIP9
bDownOver = true; l[Ko>
//nPos = fileAccessI.write (b,0,nRead); u$rSM0CJ
} %{B4M#~
catch(Exception e){e.printStackTrace ();} 1deK}5'
} [5;_XMj%
} 5h[<!f=
/:ju/~R}
f64}#E|w
//打印回应的头信息 4K0Fc^-
public void logResponseHead(HttpURLConnection con) ?W\KIp\Kn
{ <~hx ~"c
for(int i=1;;i++) _+ERX[i
{ #}+_Hy
String header=con.getHeaderFieldKey(i); ?.g="{5X
if(header!=null) RV>n Op}R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :4x&B^,53
Utility.log(header+" : "+con.getHeaderField(header)); ow4|GLU^;
else MUi#3o\f
break; 9/PX~j9O?
} 30{+gYA
} %*^s%NI
@@5JuI-!
xMA2S*%ca
public void splitterStop() nn8uFISb
{ gg&Dej2{
bStop = true; 7e:7RAX
} IXU~&5&J
}+fBJ$
,T8fo\a4
} ow7*HN*
c8oE,-~
+:3p*x%1H
/* 6Tg'9|g
**FileAccess.java 5 J 7XVe>
*//文件访问(定位，写) BYZllwxwTE
package NetFox; g+QNIM>
import java.io.*; J:dNV<A^
6.M!WK{+
$%zM Z
public class FileAccessI implements Serializable{ BWLeitS/
',s{N9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6)1xjE#
RandomAccessFile oSavedFile; .#_g.0<
long nPos; uz@lz +
4`p[t;q
vFK!LeF%
public FileAccessI() throws IOException ]//Dd/L6
{ oRHWb_$"
this("",0); cHUj6'neO
} Tl S904'
Z9UNp[0
eo<=Q|nI&
public FileAccessI(String sName,long nPos) throws IOException GC)xQZU)s
{ P`y 0FKS
oSavedFile = new RandomAccessFile(sName,"rw"); I{7Hz{
this.nPos = nPos; Bw4PxJs-
oSavedFile.seek(nPos); vJg^uf)
} Q@- h
H1e^/JD)
k-8$43
public synchronized int write(byte[] b,int nStart,int nLen) WO+_|*&
{ 4p]hY!7
int n = -1; 7Yly^
try{ /S`d?AV
oSavedFile.write(b,nStart,nLen); e[%g'}D:-
n = nLen; Ew2ksZ>B]&
} J72YZrc
catch(IOException e) o%l|16DR
{ ^w~Utx4
e.printStackTrace (); ;mXw4_{
} |\/V1
!z_VwZ#,
PHqIfH[
return n; ^:]~6p#
} J0yo@O
i]IZ0.?Y
bEl)/z*gy/
} $qk(yzY
CDGN}Q2_
u =|A
/* fMIKA72>{
**SiteInfoBean.java qW t 9Tr
*/ BZRC0^-C@
package NetFox; r&D&xsbQ
Gu\lV c
QW6\~l 4
public class SiteInfoBean { 6Ej@;]^^-
xyRZ v]K1
Z{ b($po
private String sSiteURL; //Site's URL ?iaD;:'qE
private String sFilePath; //Saved File's Path gfU!sYZ
private String sFileName; //Saved File's Name 28d=-s=[
private int nSplitter; //Count of Splited Downloading File 3&7$N#v
M\jTeB"Z
Oz7WtN
public SiteInfoBean() roE*8:Y
{//nSplitter的缺省值为5 ?o.Q
//default value of nSplitter is 5 "P{T]
this("","","",5); Qh@A7N/L
} Wo~#R
Dv[ 35[Yh
\k)(:[^FY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Zv)x-48
{ 9|RR;k[
sSiteURL= sURL; ]BBL=$*
sFilePath = sPath; "+:~#&r
sFileName = sName; ,MdK "Qa>
this.nSplitter = nSpiltter; K(B|o6[
gv,8Wo
:,BKB*a\
} l*z.20^P
>6"u{Qmr
q$6Tb
public String getSSiteURL() -P|st;?#
{ 6zJfsKf$
return sSiteURL; 8^%Nl `_2B
} a5# B&|#q
U>s$}Y:+Z
[p# }=&d
public void setSSiteURL(String value) yZ]u{LJS
{ JJ$q*
sSiteURL = value; dSm; e_s
} ULIpb
'vUx4s
^z\*; f
public String getSFilePath() %wuD4PRK
{ smN|r
return sFilePath; #DFfySH)A
} OFe?T\dQn
`@07n]KB
o7;#B)jWS
public void setSFilePath(String value) jsOid5bs
{ =vZF/r
sFilePath = value; jjrhl
} sHQ82uX
%\2w 1
26Jb{o9Z<
public String getSFileName() .y~vn[qN
{ ;VAHgIpx;
return sFileName; .#[==
} uWE :3
}L.&@P<
*c6o#[l
public void setSFileName(String value) ).b,KSi
{ #N'W+M /
sFileName = value; 1fzHmD
} l4+Bs!i`
qoXncdDHZ
c$skLz
public int getNSplitter() n6Qsug$z
{ fyE#8h_>4
return nSplitter; X|w[:[P
} mWPA]g(
l@OY8z-_
wfXm(RYM
public void setNSplitter(int nCount) nW*D
{ E'O[E=
nSplitter = nCount; zZax![Z
} bYKe5y=
} n$oHr
9Oe~e
q/lQEfR
/* ?' :v):J}
**Utility.java awic9uMH
*/ jJK`+J,i}X
package NetFox; Q'B2!9=LB
%P2l@}?a
= olmBXn/
public class Utility { yxx'g+D*
GF=rGn@,)`
hvO
public Utility() lEWF~L5=:
{ NB|yLkoDyI
Oe/\@f0bLT
'M'k$G@Z
} -FGQn |h4
n+XLZf#
//线程睡眠 F?B`rw@xr
public static void sleep(int nSecond) Qmg2lP.)
{ ^f%hhpV@
try{ Sb& $xWL
Thread.sleep(nSecond); y9xvGr[l
} >3MzsAH\
catch(Exception e) y`|86` Y
{ ,&5\`
e.printStackTrace (); R#^.8g)t
} [PW\l+i
} %A^V@0K3
ac%6eW0#
//日志 7B)m/%>3s
public static void log(String sMsg) 1z5Oi u
{ ;#Y'SK
System.err.println(sMsg); ?;0w1
} dz>2/'
D,l&^diz
QK`5KB(k'
public static void log(int sMsg) nR(v~_y[V
{ EIrAq!CA
System.err.println(sMsg); ~Bi>T15e
} S[ln||{
} 1XpG7
nUy.gAb
o#~Lb9`@U
/* fR$_=WWN>h
**TestMethod.java ' %&gER
*/ js..k*j
package NetFox; ^P}jn`4
d^(7\lw|
`i:DmIoz
public class TestMethod { @?vC4+'
PptVneujI
@$aGVEcU$
public TestMethod() LGdM40
{ ///xx/weblogic60b2_win.exe 9Gc4mwu
try{ X;&Iu{&=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |Fi{]9(G2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =f/CBYNw@V
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0;Oe&Y
fileFetch.start(); yCvP-?2
} srCpgs]h
catch(Exception e){e.printStackTrace ();} 77b^d9! ~
xMs!FMn[
b$;qtfJG
} _@5|r|P>
vk0b b3){D
|ns B'Q
public static void main(String[] args) ,` 64t'g
{ tP][o494\&
new TestMethod(); B%^W$7 q
} bt{b%r
} Ls`[7w
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