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)); "f+2_8%s+
} L1BpY-=
for(int i=0;i<nEndPos.length-1;i++) QJ?!_2Ax
{ .(ir2g
nEndPos = nStartPos[i+1]; >Fh@:M7z
} gw^+[}U#
nEndPos[nEndPos.length-1] = nFileLength; a4YyELXe
} FW,D\51pTP
} ?;Qk!t2U
HVpaVM
29oEkaX2o
//启动子线程 i:72FVo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t=#)3C`Q}
for(int i=0;i<nStartPos.length;i++) Tc:`TE=2
{ "AVc^>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bcG-js-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NGu]|p
nStartPos,nEndPos,i); mLO6`]p{H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TPuzL(ws
fileSplitterFetch.start(); !/SFEL@_B
} y-mmc}B>N
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G 2##M8:U0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z)~2{)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Nx__zC^r
nEndPos = " + nFileLength); @,vSRns
// fileSplitterFetch[nPos.length-1].start(); ececN{U/
"]<Ut{Xb
e9hQJ 1{)x
//等待子线程结束 wpdT "
//int count = 0; U<x3=P
//是否结束while循环 aryr
boolean breakWhile = false; 3h&s=e!
jiat5
smggr{-
while(!bStop) o<y7Ut
{ QXCI+Fcg
write_nPos(); 'E9jv4E$n
Utility.sleep(500); =0Mmxd&o=M
breakWhile = true; n"JrjvS
;%}
G+ToZ&f@
for(int i=0;i<nStartPos.length;i++) 5o?bF3
{ _z;N|Xe
if(!fileSplitterFetch.bDownOver) B!Y;VdX
{ Rs dACP
breakWhile = false; > 01k u
break; <q|19fH-5
} t0Uax-E(
} F9hCT)
if(breakWhile) UU_k"D~
break; *m2:iChY
TUT>*
2neiUNT
//count++; B*{CcQ<5
//if(count>4) vCJjZ%eO%D
// siteStop(); wS4zAu
} 2IGAZ%%
IzG7!K
rei<{woX
System.err.println("文件下载结束！"); cla4%|kq3Y
} 3KGDS9I
catch(Exception e){e.printStackTrace ();} j=7]"%
} qVf~\H@
fgNEq
!cfn%+0
//获得文件长度 2`; 0y M
public long getFileSize() H='`#l1
{ *@yYqI<1a
int nFileLength = -1; Tsa&R:SE
try{ ZEB1()GB
URL url = new URL(siteInfoBean.getSSiteURL()); rHMsA|xz6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {pVD`#Tl[
httpConnection.setRequestProperty("User-Agent","NetFox"); `.n[G~*w~1
8g<3J-7Mm
T^"d%au
int responseCode=httpConnection.getResponseCode(); >4;A(s`
if(responseCode>=400) pJ{sBp_$
{ ~q<UE\H
processErrorCode(responseCode); q*2ljcb55
return -2; //-2 represent access is error h5F1mr1Sa
} hNQ,U{`;^
X/?3ifP6I
C; ! )<(Vw
String sHeader; {1FYHM^
`74A'(u_
%hY+%^k.
for(int i=1;;i++) SwQb"
{ F$)Ki(mq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E_FseR6
//Utility.log(in.readLine()); T1Xm^{
sHeader=httpConnection.getHeaderFieldKey(i); U|,VH-#
if(sHeader!=null) GX\/2P7CZ
{ A\WgtM
if(sHeader.equals("Content-Length")) _,5(HETE2
{ o#G7gzw)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); # *\PU
break; ndN8eh:OR
} ^/c&Ud
} NX$$4<A1
else 0?k/vV4
break; (ZDRjBth[
} (G:$/fK
} Krz[ f
catch(IOException e){e.printStackTrace ();} ]e R1 +Nl
catch(Exception e){e.printStackTrace ();} xEGI'lt
|Zz3X
`XQM)A
Utility.log(nFileLength); FD[*mCGZ
<vOljo
haS`V
return nFileLength; xj(&EGY:
} Ot5 $~o
A\gj\&B0"
JQ!D8Ut
//保存下载信息（文件指针位置） ]e 81O#t3
private void write_nPos() Es1Yx\/:
{ #|)GarDG
try{ LKtr>u
output = new DataOutputStream(new FileOutputStream(tmpFile)); (',G Ako
output.writeInt(nStartPos.length); W.{#Pg1Da
for(int i=0;i<nStartPos.length;i++) 19h8p>Sx0
{ b>?X8)f2e
// output.writeLong(nPos); !ZHPR:k|
output.writeLong(fileSplitterFetch.nStartPos); $GPenQ~},
output.writeLong(fileSplitterFetch.nEndPos); Fod2KS;g
} {^5r5GB=*
output.close(); }>fL{};Z"
} -7>vh|3
catch(IOException e){e.printStackTrace ();} 0~Z2$`(
catch(Exception e){e.printStackTrace ();} s9zdg"c'
} UPA))Iv>
0(h *<g:
Jcy
//读取保存的下载信息（文件指针位置） {C[<7ruF
private void read_nPos() o0_RU<bWN
{ =&< s*-l[
try{ 6(VCQ{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +kmPQdO;*/
int nCount = input.readInt(); S2w|\"
nStartPos = new long[nCount]; 6uOR0L
nEndPos = new long[nCount]; [-=PK\ B
for(int i=0;i<nStartPos.length;i++) U_y)p Cd
{ 7JQ5OC3
nStartPos = input.readLong(); $*{PUj
nEndPos = input.readLong(); *4dA(N\k"
} \|L@
input.close(); A !x"*
} !i2=zlpb[
catch(IOException e){e.printStackTrace ();} y/'2WO[
catch(Exception e){e.printStackTrace ();} 7_?:R2]n
} p3qlVE
|JtdCP{
3#j%F
private void processErrorCode(int nErrorCode) ubjuuha"
{ uL1e?
System.err.println("Error Code : " + nErrorCode); &NL=Bd
} a{mtG{Wc
eh&?BP?
/#GX4&z
//停止文件下载 ~6Vs>E4G
public void siteStop() !LVWggk1
{ LsS/Sk
bStop = true; tK`sVsm>
for(int i=0;i<nStartPos.length;i++) m1heU3BUWU
fileSplitterFetch.splitterStop(); y4tM0h
E;fYL]j/oZ
DvKM[z3j
} 'p80X^g
} Zm>Q-7r9
//负责部分文件的抓取 G^ZL,{
**FileSplitterFetch.java DGz'Dn
*/ C7dy{:y`
package NetFox; U}x2,`PI
bN`oQ.Z 4
rbHrG<+7zO
import java.io.*; Xp[[ xV|
import java.net.*; 4_ztIrw
s/Fc7V!;
O[+S/6uy
public class FileSplitterFetch extends Thread { lbZ,?wm
?}e8g
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String sURL; //File URL >_!pg<{,
long nStartPos; //File Snippet Start Position 2Vxr
long nEndPos; //File Snippet End Position dQVV0)z
int nThreadID; //Thread's ID ZSuUmCm
boolean bDownOver = false; //Downing is over E{[c8l2B
boolean bStop = false; //Stop identical QXY-?0RO#
FileAccessI fileAccessI = null; //File Access interface (YVl5}V
7L|w~l7R~
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ({zt=}r,
{ p+SFeUp
this.sURL = sURL; IAf,TKfe
this.nStartPos = nStart; yv=LT~
this.nEndPos = nEnd; ^W5rL@h_
nThreadID = id; _iLXs
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z9}rT<hy
} Z$ Fh4
:WIbjI=
Ir|Q2$W2^c
public void run() M7-piRnd4
{ |}b~ss^
while(nStartPos < nEndPos && !bStop) )tl=tH/$
{ \[Op:^S
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lEIX,amwa
try{ '}dlVf
URL url = new URL(sURL); @a#qq`b;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I~\j%zD
httpConnection.setRequestProperty("User-Agent","NetFox"); -|B?pR
String sProperty = "bytes="+nStartPos+"-"; EGO;g^,
httpConnection.setRequestProperty("RANGE",sProperty); ;W]NT4p
Utility.log(sProperty); 7Oe |:Z
qUA&XUJ
x.qn$?3V]
InputStream input = httpConnection.getInputStream(); xRpL\4cs
//logResponseHead(httpConnection); zuUf:%k}I
W-<E p<7{
U~-Z`_@^-
byte[] b = new byte[1024]; `Jhu&MWg
int nRead; .\M@oF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $j0]+vT
{ m663%b(5>
nStartPos += fileAccessI.write(b,0,nRead); 8fFURk
//if(nThreadID == 1) )[yM4QFl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y;<^[
} ugcWFB5|
SoeL_#+^W
8.HqQ:?&2t
Utility.log("Thread " + nThreadID + " is over!"); P$S>=*`n U
bDownOver = true; _?#}@?
//nPos = fileAccessI.write (b,0,nRead); Yf&x]<rkCp
} XFeHkU`C
catch(Exception e){e.printStackTrace ();} KGdL1~
} :$."x '
} zRN_`U
,u7:l
~F~g$E2 }
//打印回应的头信息 S~0 mY} m
public void logResponseHead(HttpURLConnection con) 5jD2%"YUV
{ 9Slx.9f
for(int i=1;;i++) ~f0Bu:A)
{ Zm,<2BP>
String header=con.getHeaderFieldKey(i); )pLde_ k
if(header!=null) [R*UPa
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sYM3&ikyHI
Utility.log(header+" : "+con.getHeaderField(header)); e84[B.
else 4CVtXi_Y
break; hz{=@jX
} Cp=DdmR
} wZ/Zc} .
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)w_0lm'v{r
public void splitterStop() W- 5Z"m1I
{ 'AU(WHf
bStop = true; H4p N+
} %Ez=
Z8$n-0Ww
H+y(W5|2/X
} @T[}]e
T#%r\f,l0
!PJD+SrG
/* {^zieP!
**FileAccess.java 1eQa54n
*//文件访问(定位，写) 0)n#$d>
package NetFox; hvCX,^LoJ
import java.io.*; 3*C9;Q}
8$9<z
_1_CYrUc
public class FileAccessI implements Serializable{ ;zVtJG`
>KXSb@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hAq7v']m
RandomAccessFile oSavedFile; %~Vgz(/
long nPos; :MPWf4K2s
tmEF7e`(o
YLs%u=e($
public FileAccessI() throws IOException S_?{<{
{ 2k}~"!e1
this("",0); @9S3u#vP
} 'jh9n7mH
r5yp jT^
{]Tb
public FileAccessI(String sName,long nPos) throws IOException 1KwUp0%&
{ 40,u(4.m*
oSavedFile = new RandomAccessFile(sName,"rw"); l]tda(
this.nPos = nPos; g2Pa-}{
oSavedFile.seek(nPos); D >ax<t1K
} :f<:>"<
}i,LP1R
u.W}{-+kp
public synchronized int write(byte[] b,int nStart,int nLen) esE5#Yq4.k
{ J*HZ=6L
int n = -1; +pDZ,c,
try{ M.B0)
oSavedFile.write(b,nStart,nLen); e$!01Y$HI
n = nLen; JG6"5::
} vb^/DMhz
catch(IOException e) tx0`#x
{ 7nr+X Os
e.printStackTrace (); >IZ|:lsxE
} 3O %u?
,c3gW2E
bEx8dc`Q
return n; w]2tb
} Iu(j"b#
Py?EA*(d#
`*?8<Vm
} }?PvNK]",
$:&?!>H
z +NxO!y
/* P!uwhha/g
**SiteInfoBean.java St9+/Md=jQ
*/ .4I"[$?Q
package NetFox; `{1`>5
KBVW<;C$
+[W_Jz
public class SiteInfoBean { @C\>P49
V* :Q~ ^
VE_%/Fs,
private String sSiteURL; //Site's URL a+wc"RQ |
private String sFilePath; //Saved File's Path h5@v:4Jjo~
private String sFileName; //Saved File's Name R 2.y=P8N
private int nSplitter; //Count of Splited Downloading File #~ikR.-+Eq
v-^7oai
^5BLuN6
public SiteInfoBean() BNA`Cc1VV
{//nSplitter的缺省值为5 M{sn{
//default value of nSplitter is 5 ZH o#2{F
this("","","",5); ]U9f4ODt
} X{8/]'(
/Q|guJx
s#f6qj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N\Nwmx
{ 4VPJv>^
sSiteURL= sURL; a?^xEye
sFilePath = sPath; _6Ex}`fyJ
sFileName = sName; WziX1%0$n
this.nSplitter = nSpiltter; |dLA D4%
ez2rCpA
e+_~a8 -|
} ^;KL`
y2XeD=_'
dV~yIxD}C*
public String getSSiteURL() J~\`8cds
{ O-5s}RT
return sSiteURL; 0O_acO4
} S7/0B4[
R78=im7
k3:8T#N>!O
public void setSSiteURL(String value) zVSbEcr,C~
{ g{]C@,W
sSiteURL = value; uTSTBI4t
} h3Bs
)ifEgBT
yUZ;keQ_Tw
public String getSFilePath() xe4F4FC'
{ @D<KG
return sFilePath; :RYh@.
} gEejLyOag
,$lOQ7R1(
Cfz020u`g
public void setSFilePath(String value) ]i}3`e?
{ ^t|CD|,K_O
sFilePath = value; |'C{nTX
} A;pVi;7
ujo3"j[b
s@WF[S7D
public String getSFileName() sz5&P )X
{ g?(h{r`
return sFileName; ZTq"SQ>ym
} B%|cp+/
71nI`.Z
k"J[mT$b
public void setSFileName(String value) h{dR)#)GF<
{ c<'Pt4LY
sFileName = value; ?1r>t"e5
} ql|ksios
kt.y"^
?q&*|-%)_d
public int getNSplitter() ~AD%aHR
{ J9tQ@3{f
return nSplitter; 0a#2Lo
} ?qn0].
o6FSSKM
/Dn,;@ZwAi
public void setNSplitter(int nCount) mP1EWh|
{ 7TTU&7l~
nSplitter = nCount; Zcaec#
} 1:.0^?Gz
} '>GZB
^Fy{Q*p`(
g$qNK`y
/* (6xrs_ea
**Utility.java PMDx5-{A/t
*/ 4t(V)1+
package NetFox; l8"
/$'R!d5r
[Rz9Di ;
public class Utility { {b|:q>Be8
B2QC#R
63ig!-9F
public Utility() z|VQp,ra
{ H_RVGAbU
!nQ!J+ g
D[.;-4"_
} }Q7~tu
8 |2QJ
//线程睡眠 F_m[EB
public static void sleep(int nSecond) O-rHfIxY
{ _N4G[jQLJ
try{ &N{XLg>
Thread.sleep(nSecond); ,tdV-9N[O
} !n<vN@V*3d
catch(Exception e) b%w?YR
{ gNon*\a,-B
e.printStackTrace (); xWY%-CWY.
} -Y#YwBy;M
} ?8cgQf$
sN6R0YW
//日志 S>W_p~@
public static void log(String sMsg) Fdgu=qMm
{ %3L4&W_T
System.err.println(sMsg); 58x=CN\QU
} y.$/niQ%
ac8+?FpK #
}9w?[hXW"
public static void log(int sMsg) Ga5O&`h
{ n H)6mOYp
System.err.println(sMsg); y be:u
} Fa}3UVm
} =!rdn#KH
.;ptgX
|9YY8oT.
/* Qh4@Nl#Ncf
**TestMethod.java p^QEk~qw
*/ DnbT<oEL
package NetFox; Igowz7
~j%g?;#*
HAq
public class TestMethod { ,+0#.Ns$
(;RmfE'PX
xign!=
public TestMethod() MeD}S@H
{ ///xx/weblogic60b2_win.exe X,m6#vLK2
try{ dso6ZRx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V6opV&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p.(8ekh
SiteFileFetch fileFetch = new SiteFileFetch(bean); &e2|]C4
fileFetch.start(); PL;PId<9w
} HYd&.*41rE
catch(Exception e){e.printStackTrace ();} A 9I5
j<H5i}
>LvQ&fAo
} 8ZmU(m
&NvvaqJ
*V@>E2@
public static void main(String[] args) ${(c`X
{ l*~".q;S
new TestMethod(); ~ ZkSYW<
} 5u\#@% \6
} cV=0)'&<`_
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