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)); P+eKZo
} m}VM+=
for(int i=0;i<nEndPos.length-1;i++) i5hD#
{ G@S&1=nj3
nEndPos = nStartPos[i+1]; ~;-9X|
} 9?+9UlJ7K
nEndPos[nEndPos.length-1] = nFileLength; <<MjC5
} ]O:M$ $
} _i}wK?n
L{gE'jCC
,xJrXPW
//启动子线程 rl:KJ\*D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b syq*
for(int i=0;i<nStartPos.length;i++) T+"f]v
{ 8F;>5i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zIQzmvf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _BnTv$.P
nStartPos,nEndPos,i); E]^5I3=O
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /I&wj^
fileSplitterFetch.start(); _17|U K|N
} uK*Nu^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BpAB5=M0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B7NtkMK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5,+\`!g
nEndPos = " + nFileLength); )J/HkOj"V
// fileSplitterFetch[nPos.length-1].start(); uMXc0fs!$
toa-Wa{
8uG0^h}
//等待子线程结束 _3Q8n|
//int count = 0; Mjpo1dw
//是否结束while循环 @b!"joEy
boolean breakWhile = false; A3P9.mur
k/Mp6<?C:
~M?|Vn
while(!bStop) O^{1RV3:,T
{ t7#lsd`_
write_nPos(); .I?@o8'x
Utility.sleep(500); c $;\i
breakWhile = true; Qqs"?Z,P
<FFJzNc+
cErI%v}v0
for(int i=0;i<nStartPos.length;i++) bk#xiuwT
{ 5$l9@0D.\
if(!fileSplitterFetch.bDownOver) mAqDjRV1
{ sB}]yw
breakWhile = false; $,1dQeE
break; wV<7pi
} y<r}"TAf-
} Uku5wPS
if(breakWhile) :jNYP{Br
break; 4yV].2#rl"
;cP8?U
C;1PsSE+A
//count++; Q/_#k/R
//if(count>4) wuK=6RL
// siteStop(); ~bU7QLr
} pD`/_-=^h
yM$J52#d#
QrjDF>
System.err.println("文件下载结束！"); DMgBcP
} o 5Zyh26
catch(Exception e){e.printStackTrace ();} [$:,-Q@
} vd~U@-C=R
:=g.o;(/N
?#[)C=p]z
//获得文件长度 c;!g
public long getFileSize() Vb6K:ZnF
{ #;j9}N
int nFileLength = -1; i&tsYnP2
try{ 4_Rdp`x#J
URL url = new URL(siteInfoBean.getSSiteURL()); n`5WXpz4;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4KIWb~0Y
httpConnection.setRequestProperty("User-Agent","NetFox"); Cyk s
'Tf9z+0;
_'iDF
int responseCode=httpConnection.getResponseCode(); HFh /$VM
if(responseCode>=400) l)}t,!M6
{ b;vNq
processErrorCode(responseCode); ]S/G\z
return -2; //-2 represent access is error tW6#e(^l6
} u*R7zY
K^D82tP
a|x8=H
String sHeader; T&}Ye\%
V:^H4WvL\W
9`X&,S~e
for(int i=1;;i++) N=fz/CD)I
{ -q2MrJ*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $ad&#q7
//Utility.log(in.readLine()); mZoD033H
sHeader=httpConnection.getHeaderFieldKey(i); h)B!LAr
if(sHeader!=null) CyTFb$Z
{ lSCY5[?
if(sHeader.equals("Content-Length")) Z] {@H
{ JLUms
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i&F~=Q`
break; fGO*%)
} g5}7y\
} FN{/.?w(
else >ZCo 8aK
break; 9+VF<;Xw
} JLW$+62
} K`+vfqX
catch(IOException e){e.printStackTrace ();} ?[SVqj2-
catch(Exception e){e.printStackTrace ();} &l^n4
BR3mAF
wixD\t59X
Utility.log(nFileLength); rgR?wXW]jE
elKx]%k*)
y9 uVCR
return nFileLength; i7v/A&Rc
} Z[;#|$J
*PcVSEP/0
@,6ST0xT (
//保存下载信息（文件指针位置） &wGg6$
private void write_nPos() sMJ#<w}Q
{ g\J)= ,ju,
try{ )+B=z}:Nfz
output = new DataOutputStream(new FileOutputStream(tmpFile)); GMb!Q0I8
output.writeInt(nStartPos.length); W:B}u\)C
for(int i=0;i<nStartPos.length;i++) = o+7xom
{ @^HwrwRA
// output.writeLong(nPos); }:^XX0:FK
output.writeLong(fileSplitterFetch.nStartPos); KZ\dB;W<|
output.writeLong(fileSplitterFetch.nEndPos); sA2o2~AmM
} jEE_D +K
output.close(); Q!)z)-hI
} bw;iz,Z
catch(IOException e){e.printStackTrace ();} N l|^o{#
catch(Exception e){e.printStackTrace ();} }~GV'7d1
} Q0SW;o7
XPVV+.
g^n;IE$B
//读取保存的下载信息（文件指针位置） ORtg>az\%
private void read_nPos() ;qG1r@o
{ x 8M#t(hw
try{ h9Z[z73_a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |+mOH#Aty
int nCount = input.readInt(); 5:_~mlfi
nStartPos = new long[nCount]; I$Eg$q
nEndPos = new long[nCount]; hLn&5jYHvt
for(int i=0;i<nStartPos.length;i++) #mTMt;x
{ Ctj8tK$D
nStartPos = input.readLong(); )+k[uokj
nEndPos = input.readLong(); jDp]R_i
} JchA=n
input.close(); p}r yKW\cJ
} 1J+3a-0
catch(IOException e){e.printStackTrace ();} 59/Q*7ZJ
catch(Exception e){e.printStackTrace ();} !xJFr6G~8
} =%)})
{V=vnL--
o] S`+ZcV
private void processErrorCode(int nErrorCode) Lqq*Nr
{ Q%$i@JH`m
System.err.println("Error Code : " + nErrorCode); M3PVixli3
} J;"nm3[.q
\|Y{jG<cu
+E)e1:8
//停止文件下载 {;;eOxOP|
public void siteStop() \hu':@}
{ 8}J(c=4Gk
bStop = true; i!y\WaCp
for(int i=0;i<nStartPos.length;i++) ?^eJ:
fileSplitterFetch.splitterStop(); f5N<3m=
w[M5M2CF
xz="|HD);
} BMe72
} myffYK,
//负责部分文件的抓取 [I_BCf
**FileSplitterFetch.java a\Tr!Be,
*/ {MA@A5
package NetFox; =cknE=
m_~y
!__D}k,
import java.io.*; @gY'YA8m
import java.net.*; 0yKwH\S
fg< (bXC
+-'`Q Ae
public class FileSplitterFetch extends Thread { ?F!W#
XZ!cW=bqS
7-(>"75Q|
String sURL; //File URL MQjG<O\
long nStartPos; //File Snippet Start Position EOofa6f&l
long nEndPos; //File Snippet End Position +6wx58.B&
int nThreadID; //Thread's ID 6@i|Kw(:
boolean bDownOver = false; //Downing is over ~}Kp
boolean bStop = false; //Stop identical z`;&bg\8
FileAccessI fileAccessI = null; //File Access interface S/KVN(Z
)|MIWgfWN
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException P~n8EO1r
{ w 5!ndu
this.sURL = sURL; KC#kss
this.nStartPos = nStart; J,.j_ii`!
this.nEndPos = nEnd; WFQ*s4 R(
nThreadID = id; q.U*X5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !4i,%Z&6
} i#Ne'q;T
ll 6]W~[ZC
EaJDz`T}
public void run() ~r{\WZ.
{ J~M H_N
while(nStartPos < nEndPos && !bStop) |;X?">7NW
{ N:"M&EUM
7AS.)Q#=x
Smi%dp.
try{ H^]Nmd8Q)
URL url = new URL(sURL); Q@ykQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L?AM&w-cg9
httpConnection.setRequestProperty("User-Agent","NetFox"); -ryDsq
String sProperty = "bytes="+nStartPos+"-"; Tyg$`\#
httpConnection.setRequestProperty("RANGE",sProperty); /h1dm,
Utility.log(sProperty); 8Pl+yiB/o`
w++B-_
pjaiAe!k
InputStream input = httpConnection.getInputStream(); Tz+HIUIxF
//logResponseHead(httpConnection); $,xtif0
-[i40 1
h[Ndtq>3{
byte[] b = new byte[1024]; 2V#c[%vI
int nRead; d08`42Z69
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Tb5$
{ r\4*\
nStartPos += fileAccessI.write(b,0,nRead); OL,/-;z6
//if(nThreadID == 1) !C9ps]6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $]Q*E4(kV9
} .rt8]%
!:]s M-cCt
>!:$@!6L
Utility.log("Thread " + nThreadID + " is over!"); 2GHXn:V
bDownOver = true; i*mZi4URN
//nPos = fileAccessI.write (b,0,nRead); '7S!6kd?
} 34/]m/2NZK
catch(Exception e){e.printStackTrace ();} lGD%R'}
} HPu/. oE
} krEH`f
L:|X/c9r[
EqNz L*E
//打印回应的头信息 ]Ct`4pA
public void logResponseHead(HttpURLConnection con) = ]dz1~/
{ Q#yu(
for(int i=1;;i++) 0})7of
{ xI.Orpw
String header=con.getHeaderFieldKey(i); 4?P%M"\Iv
if(header!=null) Fi?U)T+%+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lp37irI:
Utility.log(header+" : "+con.getHeaderField(header)); JLFFh!J
else J};u25:}
break; A{DIp+
} WI*^+E&=*
} c%xED%X9
F]URf&U
t z +
public void splitterStop() wHBHkz
{ CrRQPgl+u
bStop = true; 60U{ e}Mkb
} !0!P.Q8>&
i/C -{+}U
zR3lX}g
} PMz{8 F
[]6ShcqJ[v
r?Zy-yQ
/* C{d8~6
**FileAccess.java `g4Ekp'Rp[
*//文件访问(定位，写) pQ[o3p!&9
package NetFox; !_^{udB}
import java.io.*; v;N1'
@&i#S}%/
+[X.-,yW
public class FileAccessI implements Serializable{ a`[?,W:q
|2t7G9[n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 VrAXOUJw6
RandomAccessFile oSavedFile; 0,"n-5Im
long nPos; u@:=qd=\
c1)BGy li
OTNZ!U/)j
public FileAccessI() throws IOException Hz!U_?
{ qJbhPY8Ak
this("",0); [i<$ZP
} 8a":[Q[
f2R+5`$
-Z/6;2Q
public FileAccessI(String sName,long nPos) throws IOException c|R3,<Q]
{ `/gEKrhL-
oSavedFile = new RandomAccessFile(sName,"rw"); BW;=i.
this.nPos = nPos; (TbB?X}
oSavedFile.seek(nPos); ||*&g2Y
} A^= Hu,"e
U:pLnNp`
fRv S@
public synchronized int write(byte[] b,int nStart,int nLen) :) Fp B"
{ YQB]t=Ha
int n = -1; QJ(e*/
try{ YfrTvKX
oSavedFile.write(b,nStart,nLen); 4? /ot;>2
n = nLen; ~'Qpf 8)
} ^%4( %68
catch(IOException e) 5wE !_ng>|
{ &ESR1$)'P
e.printStackTrace (); @LkW_
} ![X.%
]Nd'%M
tx|"v|&e2
return n; mAYr<=
} X"qbB4(I
6%tiB?
oRvm*"8B
} x#}j3" PP
2U+z~
:+gCO!9Y
/* q*<J$PI
**SiteInfoBean.java MSYLkQ}_b
*/ eqUn8<<s
package NetFox; Z>MJ0J76]
$V{- @=
T0np<l]A
public class SiteInfoBean { w'!}(Z5X?
[r~rIb%Zj
\3y=0
private String sSiteURL; //Site's URL *C:q _/
private String sFilePath; //Saved File's Path 6!Tf'#TV~!
private String sFileName; //Saved File's Name Lct+cKKU
private int nSplitter; //Count of Splited Downloading File x1hs19s
CgTQGJ}-
/kviO@jm4(
public SiteInfoBean() E{k%d39>
{//nSplitter的缺省值为5 g)r,q&*
//default value of nSplitter is 5 ~_l:b
this("","","",5); P".qL5
} -)->Jx:{
l`5}i|4KTW
\Dsl7s=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i]^*J1a
{ E<m"en&v
sSiteURL= sURL; -"JE-n
sFilePath = sPath; n4d(`
sFileName = sName; Z]>e& N
this.nSplitter = nSpiltter; .D2ub/er
0 *Yivx6
|#khwH
} Nno={i1jk
*}WqYqOow
s)&R W#:X
public String getSSiteURL() {*]=qSz
{ '?!<I
return sSiteURL; *.;}OX^X
} Y @ ,e
])ZJ1QL1
BKjPmrZ|
public void setSSiteURL(String value) ewff(e9
{ 2Z1(J% 7
sSiteURL = value; K v>#
} z )}wo3
8'_ ]gfF
VTX'f2\
public String getSFilePath() ,vY I O
{ u #QSa$P
return sFilePath; [?r\b
} ?Kz` O>"6
6`$z*C2{
FVLA^$5c
public void setSFilePath(String value) x?k |i}Q
{ bA9dbe
sFilePath = value; w!Lb;4x ?
} nOoh2jUM
E=U^T/
^~kFC/tQ
public String getSFileName() "@<g'T0
{ /)<7$
return sFileName; 0BwQ!B.
} 9lwo/(s
6nk|*HPz
JC?V].) y5
public void setSFileName(String value) *q9$SDm
{ )da8Ru
sFileName = value; !m.')\4<
} 2!& ;ZcT,
K0!#l Br
C&K(({5O
public int getNSplitter() E]Gq!fA&<
{ ;0}"2aGY
return nSplitter; Z"8cGN'
} 2OOj8JS
y]z#??
B!C32~[
public void setNSplitter(int nCount) 3G0\i!*t
{ [8g\pPQ
nSplitter = nCount; !~DkA7i55
} i*rv_G|(Zj
} +( 7vmC.
KE1@z]
]tV{#iIJ*
/* *xNjhR]7v
**Utility.java HDG"a&$
*/ FQ&VM6_
package NetFox; SxQDqoA~
;@\JscNJ|
x~,?Zj)n?C
public class Utility { ll^O+>1dO
e/I{N0SR
o~N-x*
public Utility() `)_FO]m}jS
{ 6E%k{ r
.:Xe*Q
?fwr:aP~
} t-{OP?cE1
jS)-COk
//线程睡眠 )n61IqrW
public static void sleep(int nSecond) c^UM(bW
{ Tfs9<k>G#
try{ j[ YTg]
Thread.sleep(nSecond); 9_^V1+
} 78A4n C
catch(Exception e) $w}aX0dK&
{ %ieAY-<"
e.printStackTrace (); q:eAL'OkM
} JugQ +0
} F#9KMu<<cI
l@9:VhU(
//日志 _E-GHj>k z
public static void log(String sMsg) SQCuY<mD
{ E0'6!9y
System.err.println(sMsg); ::t!W7W
} PU\q.y0R
#.K&]OV/88
PltPIu)F
public static void log(int sMsg) uB9+E%jOdQ
{ G!Q)?N
System.err.println(sMsg); {i?K~| h
} a.Vs>1
} ITOGD
?7dDQI7^(
RLr-xg$K-t
/* dz DssAHy
**TestMethod.java .j,&/y&
*/ >@\-m
package NetFox; 2z l
4}b:..Ku
+DDvM;31w
public class TestMethod { 6H9]]Unju
[IW7]Fv<F
dv>zK#!
public TestMethod() p_N=V. w
{ ///xx/weblogic60b2_win.exe ozr+6z
try{ sVf7g?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r F-yD1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .5zJ bZ9
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;]e"bX
fileFetch.start(); V)@scB|>,
} N($]))~3&
catch(Exception e){e.printStackTrace ();} =sJHnWL[
[C#pMLp,~
=1uI >[aN
} Np)!23 "
{RO=4ba{J
&}?e:PEy
public static void main(String[] args) nhxl#
{ l#:Q V:
new TestMethod(); r#}%sof
} mcracj[B
} Q?q m~wD
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