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)); B9p?8.[
} s { #3r
for(int i=0;i<nEndPos.length-1;i++) 7Q\|=$2
{ mc=LP>uoS
nEndPos = nStartPos[i+1]; 8!.ojdyn
} +]=e;LN$0
nEndPos[nEndPos.length-1] = nFileLength; EY*(Bw
} fYKOJ5f
} C{TA.\
.MO\uh0N
" \I4u{zC
//启动子线程 4iSa7YqhBT
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RMMd#/A@}
for(int i=0;i<nStartPos.length;i++) %X#zj"
{ ~l;[@jsw F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2,ECYie^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )`^p%k
nStartPos,nEndPos,i); /Mb"V5S(W
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %%(R@kh9
fileSplitterFetch.start(); G\|,5HED
} s4&^D<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h-iJlm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rG,5[/l
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3u%{dGa
nEndPos = " + nFileLength); z-M3
// fileSplitterFetch[nPos.length-1].start(); 9x,RvWTb
>S$Z
ss;R8:5
//等待子线程结束 xsWur(>]
//int count = 0; 5 ae2<Y=
//是否结束while循环 'SQG>F Uy
boolean breakWhile = false; ,{\Bze1fn
nUkaz*4qU
'_|h6<.k[
while(!bStop) !i=nSqW
{ [M+f-kl
write_nPos(); J2uZmEt
Utility.sleep(500); N0#JOu}~
breakWhile = true; [+qCs7'
v[Kxja;
zYl#4O`=c
for(int i=0;i<nStartPos.length;i++) C8F7bG8c
{ }fp-5
if(!fileSplitterFetch.bDownOver) 3fN.bU9_
{ t&?im<
breakWhile = false; }9nDo*A"}
break; 9"g6C<
} R8.CC1Ix
} $-[CG7VgX%
if(breakWhile) M'_9A
break; Tw +
`xrmT t X
5dZ|!
//count++; 3sd"nR?aX
//if(count>4) odIZo|dv
// siteStop(); \U@rg4
} ?-1r$31p
m&|`x
7FRmx4(!
System.err.println("文件下载结束！"); IIq1\khh
} ;5@ t[r
catch(Exception e){e.printStackTrace ();} &+G"k~%
} {rcnM7 S1L
MDF%\Sx
0OGCilOb*
//获得文件长度 ZJlEKib%2
public long getFileSize() z0/} !
{ >[X{LI(_<<
int nFileLength = -1; 6~*9;!th
try{ 4DTzSy:x
URL url = new URL(siteInfoBean.getSSiteURL()); "s\L~R.&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3"F`ZJ]=
httpConnection.setRequestProperty("User-Agent","NetFox"); $+7`Dy!
86z]<p (
6Zn @2PGEl
int responseCode=httpConnection.getResponseCode(); 4b:s<$TZ
if(responseCode>=400) 2B,] -Mu)
{ F{ELSKcp.
processErrorCode(responseCode); ;'-olW~
return -2; //-2 represent access is error Y@ZaJ@%9@
} xU%w=0z<
_V\Bp=9W
dg^L=
String sHeader; !+:ov'F
\e`~i@) ~Z
}x&N^Ky3c
for(int i=1;;i++) Un6/e/6,
{ Bn!$UUC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >2By +/!X
//Utility.log(in.readLine()); _v* nlc
sHeader=httpConnection.getHeaderFieldKey(i); j) ,,"54*
if(sHeader!=null) %TsPyiYl
{ s@fTj$h
if(sHeader.equals("Content-Length")) Wa?; ^T
{ Vx @|O%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <x!GE>sf+
break; YBnA+l*
} itzyCw2|#
} [V}S<Xp
else zq%D/H6J,
break; frBX{L
} ,\v91Rp~?
} {aM<{_v
catch(IOException e){e.printStackTrace ();} \lSU
catch(Exception e){e.printStackTrace ();} pC_O:f>vJ
nVJPR
6)BR+U
Utility.log(nFileLength); J+f!Ar
"]-Xmdk09
u<nLag
return nFileLength; 5/O'R9A4
} ++DG5`
wfjnA~1h
Dr6A,3B
//保存下载信息（文件指针位置） bBY^+c<
private void write_nPos() mq%<6/YU
{ /x1MPP>fu
try{ +d|mR9^([
output = new DataOutputStream(new FileOutputStream(tmpFile)); asC_$tsMe
output.writeInt(nStartPos.length); c*R/]Dn
for(int i=0;i<nStartPos.length;i++) ?Mee 6
{ Reu*Pe
// output.writeLong(nPos); owPm/F
output.writeLong(fileSplitterFetch.nStartPos); :\=CRaA
output.writeLong(fileSplitterFetch.nEndPos); +b3^.wkq
} r/*=%~*
output.close(); oP4GEr
} rLX4jT^
catch(IOException e){e.printStackTrace ();} *cO sv
catch(Exception e){e.printStackTrace ();} j+HHQd7Y
} 'KPASfC
a/< Csad
_@R0x#p5M
//读取保存的下载信息（文件指针位置） [{X^c.8G)
private void read_nPos() ?:Bv iF);/
{ )IJQeC
try{ *FJZiPy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); YX*Qd$chZ
int nCount = input.readInt(); OaL\w D^
nStartPos = new long[nCount]; R-P-i0~
nEndPos = new long[nCount]; K+6e?5t
for(int i=0;i<nStartPos.length;i++) y7^{yS[,
{ kQ
nStartPos = input.readLong(); `ImE% r!
nEndPos = input.readLong(); 'fL"txW
} uWrQ&}@
input.close(); XbQlHfrS
} u_).f<mUdF
catch(IOException e){e.printStackTrace ();} {f{ZHi|
catch(Exception e){e.printStackTrace ();} Y{*u&^0{
} nF5qw>t#
c_" ~n|
Ig5L$bAM~
private void processErrorCode(int nErrorCode) P<K){V
{ B*gdgM*`
System.err.println("Error Code : " + nErrorCode); O=9-Qv|
} r4,VTy2Qe
CpQN,-4
$u/E\l
//停止文件下载 IMk'#)
public void siteStop() b9XW9O`B
{ zuJtpMn
bStop = true; OnWx#84
for(int i=0;i<nStartPos.length;i++) w4LScvBg
fileSplitterFetch.splitterStop(); >*wtbkU
(@#M!'
LjU'z#
} !u]1dxa
} 4Yl;
//负责部分文件的抓取 X(7qZ P~
**FileSplitterFetch.java oc^Br~ Th
*/ Dk5Zh+^
package NetFox; %e@HZ"V
|!F5.%PY
[NFNzwUB
import java.io.*; wW"z
import java.net.*; ,<:!NF9
W14Vm(`N
( 9]_ HW[
public class FileSplitterFetch extends Thread { c`fG1s
)yo a
aTzjm`F0
String sURL; //File URL !cGDy/|
long nStartPos; //File Snippet Start Position jP~Z`yf
long nEndPos; //File Snippet End Position rS1fK1dys
int nThreadID; //Thread's ID 1bw{q.cmD
boolean bDownOver = false; //Downing is over ;@ [ 0x
boolean bStop = false; //Stop identical G"T',~
FileAccessI fileAccessI = null; //File Access interface Z;h<6[(
A*|cdY]HP
h!m_PgRSs
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X=C1/4wU
{ @zgdq
this.sURL = sURL; A_;8IlW
this.nStartPos = nStart; F_bF
this.nEndPos = nEnd; .I@CS>j
nThreadID = id; LOTP*Syjf
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <40rYr$/J
} 9h0X&1u
S"wg2X<
.Q)|vq^
public void run() K\)Td+~jc
{ n$[f94d=
while(nStartPos < nEndPos && !bStop) w}{5#
{ zm,@]!wI
we#wH-
-n0C4kZ2o
try{ Skz|*n|eY
URL url = new URL(sURL); .%zy`n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GQ_p-/p R
httpConnection.setRequestProperty("User-Agent","NetFox"); \cLSf=
String sProperty = "bytes="+nStartPos+"-"; 0<TD/1wN
httpConnection.setRequestProperty("RANGE",sProperty); GHQ;hN:
Utility.log(sProperty); F} d
QORN9SY
?:Y#Tbi3
InputStream input = httpConnection.getInputStream(); S!{t6'8K
//logResponseHead(httpConnection); Jl "mL
n8hRaNHl2
Zatf9yGD
byte[] b = new byte[1024]; qT/Do?Y
int nRead; 6{qIU}!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +-B^Z On
{ 6:% L![FX
nStartPos += fileAccessI.write(b,0,nRead); zS< jd~
//if(nThreadID == 1) 2Dd|~{%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r 6eb}z!i
} v=95_l
8L*GE
8J)xzp`*)
Utility.log("Thread " + nThreadID + " is over!"); ~}ET?Q7t
bDownOver = true; .qA{xbu
//nPos = fileAccessI.write (b,0,nRead); 1&:@
} P_u|-~|\
catch(Exception e){e.printStackTrace ();} f+.T^es
} 7E!7"2e a
} .q][? mW3
>\w&6i~
8_K60eXz
//打印回应的头信息 3DaQo0N
public void logResponseHead(HttpURLConnection con) =_]2&(?
{ "S&%w8V
for(int i=1;;i++) >]=j'+]
{ na^sBq?\
String header=con.getHeaderFieldKey(i); MuBx#M/
if(header!=null) ouHu8)q'r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @u._"/K
Utility.log(header+" : "+con.getHeaderField(header)); *1@:'rJ
else umLb+GbI4
break; xug)aE
} h3gWOU
} IHC1G1KW=A
_8G>&K3T<
g+PPW88P;
public void splitterStop() E0oU$IB
{ rd3j1U
bStop = true; N-w(e
} iqW1#)3'R
/+e~E;3bO
iK{T^vvk
} %PJhy2
O--7<Q\
c<#<k}y
/* \M]-bw`
**FileAccess.java ^Y{D^\},
*//文件访问(定位，写) ~Ki`Ze"x
package NetFox; H6aM&r9}
import java.io.*; ):EBgg4-N
!G_jGc=v
D@X+{
public class FileAccessI implements Serializable{ YDmWN#
r.0oxH']
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A"Q@W<.
RandomAccessFile oSavedFile; *^ \FIUd
long nPos; 2i|B=D(
2q}..
=8=!Yc(>
public FileAccessI() throws IOException hY<{t.ws
{ 9j*0D("
this("",0); N~ANjn/wL
} +\#Fd
BKU'`5`
z&4~x!-_
public FileAccessI(String sName,long nPos) throws IOException fRTo.u
{ Mp\<cE
oSavedFile = new RandomAccessFile(sName,"rw"); 6aOp[-Le
this.nPos = nPos; z1,tJH0
oSavedFile.seek(nPos); 1px\K8
} nws"RcP+Z
bXM/2Z?6
}jF+`!*!
public synchronized int write(byte[] b,int nStart,int nLen) 6ri\>QrF
{ *@V*~^V"J[
int n = -1; +Zk,2ri
try{ ep(g`e
oSavedFile.write(b,nStart,nLen); U\+&cob.
n = nLen; 5+X_4lEJK(
} !.fw,!}hOD
catch(IOException e) `"k9wC1
{ 6@4n'w{"
e.printStackTrace (); K X]oE+:
} i[semo\E
/-0' Qa+*
cy~oPj]j
return n; j?n+>/sG,
} P"7ow-
y,+[$u7h
@LLTB(@wR
} \)m"3yY
U=Bn>F}y\
>qT'z$
/* klWYuStZ
**SiteInfoBean.java k5+]SG`]]
*/ ;BH>3VK
package NetFox; J7-^F)lu-
o4=Yu7L
Gk~l,wV>
public class SiteInfoBean { 1K|@h&@
g?qKNY
"PpjoM ~
private String sSiteURL; //Site's URL \Mi#{0f+q
private String sFilePath; //Saved File's Path #I`ms$j%
private String sFileName; //Saved File's Name iRmQ5ezk
private int nSplitter; //Count of Splited Downloading File CBD_a#K{
kRIB<@{
F@YV]u>N
public SiteInfoBean() lWy=)^)4
{//nSplitter的缺省值为5 4f1D*id*`#
//default value of nSplitter is 5 qJ[@:&:
this("","","",5); hhRaJ
} &:?e&
9(VRq^Z1
DpL8'Dib
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :_d3//|
{ w!q&
sSiteURL= sURL; I6OSC&A`
sFilePath = sPath; CdhSp$>
sFileName = sName; :7;[`bm(G
this.nSplitter = nSpiltter; &+nRIv S_`
J l7z|QS
H)JS0 G0
} {sS_|sX
K^i"9D)A
,9/5T:2
public String getSSiteURL() Ex($
{ 6GOcI#C9C
return sSiteURL; V;9 }7mw
} Ht=$] Px
J^H=i)A
IKf`[_,t]
public void setSSiteURL(String value) |PM m?2^R
{ j.c8}r&
sSiteURL = value; .`LgYW
} @oH[SWx
{tzxA_
_dmL}t-
public String getSFilePath() sj9D
{ Ob&W_D^=N
return sFilePath; y' tRANxQ
} $@87?Ab
UxPGv;F
-ID!pTvW
public void setSFilePath(String value) Q&+c.S
{ }]h\/,
sFilePath = value; *PB/iVH%6
} \5[-Ml
Kd{#r/HZ
r<FQX3
public String getSFileName() 5t'Fv<g
{ J@bW^>g*6u
return sFileName; Lbq_~
} SgSk!lj
x1DVD!0~{
_.f@Y`4d
public void setSFileName(String value) e(\Q)re5Q
{ zHxmA
sFileName = value; TU%"jb5
} 0^\/ERK
QAaF@Do
T]2U fi.
public int getNSplitter() U1^l+G^,~
{ k&DGJ5m$.
return nSplitter; !`C?nY
} tBl#o ^
/VtlG+dLl
Z t`j\^4n
public void setNSplitter(int nCount) 91;HiILgT
{ ?Leyz
nSplitter = nCount; (@?eLJlT
} U?6yke
} ^uBwj}6
!1-&Y'+
V [4n'LcE
/* FU]4oKx
**Utility.java 9}n,@@
*/ W8.j/K:
package NetFox; 2 zl~>3S
1#!@["
oWrE2U;
public class Utility { "z/V%ZK~f
;vUxO<cKFq
{h^c
public Utility() <[8@5?&&
{ f=oeF]=I"
=L16hDk o
fIEw(k<*
} C@)pmSQ
rys<-i(
//线程睡眠 /d]~ly @uI
public static void sleep(int nSecond) 3jg'1^c
{ y1Z1=U*!
try{ 8}K"IW
Thread.sleep(nSecond); qp1\I$Y
} 4f jC
catch(Exception e) K!7q!%Ju
{ Z%;)@0~f
e.printStackTrace (); )BlJ|M
} zkG>u,B}
} 3*2I$e!Jt
^cb)f_90
//日志 n>T:2PQ3
public static void log(String sMsg) [edH%S}\
{ r+TK5|ke
System.err.println(sMsg); aL 8Gnqf2
} i?W]*V~ply
.S6ji~;r
CjmV+%b4
public static void log(int sMsg) 9RB`$5F;
{ l<n5gfJ
System.err.println(sMsg); 1 Xa+%n9
} wVQdUtmk
} ,$PFI(Whk
xi.IRAZX
a G@nErdW
/* yYBNH1
**TestMethod.java 5R"2Wd
*/ +0U#.|?
package NetFox; z[Z2H5[
hafECs
4D GY6PS
public class TestMethod { Y@ObwKcG
qdO[d|d
m1i4,
public TestMethod() n/?eZx1
{ ///xx/weblogic60b2_win.exe BMY>a
try{ u'=(&><
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'hy?jQ'|e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $wgc vySx
SiteFileFetch fileFetch = new SiteFileFetch(bean); E0T&GR@.
fileFetch.start(); ?;+^
} p}&Md-$1
catch(Exception e){e.printStackTrace ();} y]<#%Fh
Wge ho
hRRkFz/0&
} u8^Y,LN
W?=$V>)
7Zo&+
public static void main(String[] args) 7}A5u,.,ht
{ =g >.X9lr
new TestMethod(); Pu-p7:99;'
} RP(a,D|
} KS?mw`Nr
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