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?k#c
} \4roM1&[
for(int i=0;i<nEndPos.length-1;i++) u^]Z{K_B
{ ^fxS=Qs+
nEndPos = nStartPos[i+1]; 8PwPI%Pb
} 2)47$eu
nEndPos[nEndPos.length-1] = nFileLength; o&U/e\zy
} Cy'! >
} G.sf>.[
3IDX3cM9
-q}I; cH
//启动子线程 :dj=kuUTbu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YTYCv7
for(int i=0;i<nStartPos.length;i++) e? n8S
{ &<oDl_^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #i0f}&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a&s&6Q|Y
nStartPos,nEndPos,i); Q!v]njCIB7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2RC@Fu~zaU
fileSplitterFetch.start(); dn|OY.`|
} NGOyd1$7N
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?D S|vCae
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2kVQ#JyuRI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6HR^q
nEndPos = " + nFileLength); V}+Ui]ie|I
// fileSplitterFetch[nPos.length-1].start(); TC^fyxq
2&d|L|->
DS6g_SS3
//等待子线程结束 +n&9ZCH
//int count = 0; mUjM5ceAXO
//是否结束while循环 o`}(1$a>
boolean breakWhile = false; =Z}=nS?4
,1|0]:
=X}s^KbI{
while(!bStop) TOXZl3s5#
{ fT
write_nPos(); vDp|9VY?
Utility.sleep(500); /dq(Z"O_
breakWhile = true; n>i}O!agg
e.?;mD
f~Q]"I8w
for(int i=0;i<nStartPos.length;i++) Xwt}WSdF`k
{ /E<:=DD<
if(!fileSplitterFetch.bDownOver) 9>hK4&m^
{ TxXX}6
breakWhile = false; <A@qN95m
break; .YxcXe3#
} a5@XD_b
} ;iTZzmB
if(breakWhile) );oE^3]f
break; +N:=|u.g
eL{6;.C
LQ3J$N
//count++; ^muPjM+D
//if(count>4) ^P}c0}^
// siteStop(); NG?-dkD
} bbxo!K m"
)ME'qA3K
2!;U.+(
System.err.println("文件下载结束！"); "E}38
} l"app]uVZ
catch(Exception e){e.printStackTrace ();} >^ijj`{d
} hz*H,E!>
{axMS yp;
pA?2UZ
//获得文件长度 w~l%xiC
public long getFileSize() ?QG?F9?
{ Zia<$kAO
int nFileLength = -1; ~5sH`w~vQ
try{ c&;Xjy
URL url = new URL(siteInfoBean.getSSiteURL()); BNpc-O~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :Wl`8p4]
httpConnection.setRequestProperty("User-Agent","NetFox"); Z2^B.r#
`=JGlN7
6UnWtLE
int responseCode=httpConnection.getResponseCode(); m(eR Wx&pZ
if(responseCode>=400) Bl!R bh\
{ DfV'1s4y
processErrorCode(responseCode); >{@:p`*
return -2; //-2 represent access is error {u{8QKeC
} ZtH{2j0
`d6,]'
)9'Zb`n
String sHeader; PWbi`qF)r
odNHyJS0
%"g;K
for(int i=1;;i++) 3?:?dy(3z
{ z((9vi W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )h,-zAnZ
//Utility.log(in.readLine()); j^qI~|#
sHeader=httpConnection.getHeaderFieldKey(i); ".:]?Lvt
if(sHeader!=null) n+%tu"e
{ cLyed3uU
if(sHeader.equals("Content-Length")) fZF.eRP'
{ `(Ij@84
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7zEpuw
break; Zq\Vq:MX
} Q3|I.I e
} z)0%gd|
else $mLiEsJ
break; v7@O ,%
} BOf)27)
} IM$I=5ye
catch(IOException e){e.printStackTrace ();} fOkB|E]
catch(Exception e){e.printStackTrace ();} +3%i7
)*T<s
/o]j
Utility.log(nFileLength); Jl|^
2E_*'RT
fgEMn;
return nFileLength; ;/|3U7{c
} +U= !svE
i8H!4l
w;(B4^?
//保存下载信息（文件指针位置） XX|wle1Kg
private void write_nPos() F-I\x
{ pSh$#]mZ`
try{ y&{ Z"+B5
output = new DataOutputStream(new FileOutputStream(tmpFile)); d0CFMy6
output.writeInt(nStartPos.length); }&:F,q*
for(int i=0;i<nStartPos.length;i++) r,-9]?i
{ %5|DdpES
// output.writeLong(nPos); 'W]oQLD^R
output.writeLong(fileSplitterFetch.nStartPos); N_qKIc_R
output.writeLong(fileSplitterFetch.nEndPos); @!:_r5R~N
} o; Ns-=
output.close(); &7m)K>E27
} 6kM'f}t[C
catch(IOException e){e.printStackTrace ();} ;gmfWHB<
catch(Exception e){e.printStackTrace ();} Y%A KN
} c3G&)gU4q
?2$0aq
j~VHU89
//读取保存的下载信息（文件指针位置） `.F+T)G
private void read_nPos() PML+$
{ j+7ok 5J#
try{ ZFO*D79:K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;)gNe:Q
int nCount = input.readInt(); O| zLD
nStartPos = new long[nCount]; /aHx'TG
nEndPos = new long[nCount]; wc7F45l4
for(int i=0;i<nStartPos.length;i++) Q]NGd 0J
{ ^tY$pPA
nStartPos = input.readLong(); #Y'svn1H
nEndPos = input.readLong(); 2*1FW v
} D|rcSa.M
input.close(); \QKr2|
} kx_PMpc
catch(IOException e){e.printStackTrace ();} i1JWdHt
catch(Exception e){e.printStackTrace ();} jXALN
} dgsD~.((A
n`af2I2
gdVajOAu
private void processErrorCode(int nErrorCode) 0&k!=gj:>Z
{ cgvD>VUw
System.err.println("Error Code : " + nErrorCode); 6q]`??g.
} JD1D(
$bi@,&t;
m"RE[dQ
//停止文件下载 >iIUS
public void siteStop() 6ISDY>p
{ L.M|o
bStop = true; q\gvX 76a
for(int i=0;i<nStartPos.length;i++) mbm|~UwD
fileSplitterFetch.splitterStop(); ;%tu;
&}/h[v_#'
oy!Dm4F
} %/(>>*}Kw|
} A7X-),D
//负责部分文件的抓取 |~I-
**FileSplitterFetch.java 'ffOFIz|=I
*/ |L"!^Y#=D
package NetFox; byUz
[6Nw)r(a(
zLHE;
import java.io.*; oI6o$C
import java.net.*; gQ=g,X4
QC\][I>
U%,N"]`
public class FileSplitterFetch extends Thread { o)hQ]d
9BM 8
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String sURL; //File URL zrJ/Fs+s
long nStartPos; //File Snippet Start Position u/2!v(
long nEndPos; //File Snippet End Position s*0PJ\E2
int nThreadID; //Thread's ID t%f6P
boolean bDownOver = false; //Downing is over wWNHZv&
boolean bStop = false; //Stop identical U'tfsf/V
FileAccessI fileAccessI = null; //File Access interface 0 w#[?.
Sn lKPd
&R "Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "x)xjL
{ F]SA1ry
this.sURL = sURL; CL-mt5Kx#7
this.nStartPos = nStart; {,aI0bw;
this.nEndPos = nEnd; 7>`VZ?
nThreadID = id; *NDM{WB|)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $MT'ZM
} CNiUHUD
xXktMlI
D/&^Y'|T
public void run() iS"(
{ -OS&(7
while(nStartPos < nEndPos && !bStop) 02~+$R]L
{ ZAG iaq
JM@}+pX
krC4O2Fkj
try{ ?5<Q+G0r
URL url = new URL(sURL); UA|A>c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x1}7c9nK
httpConnection.setRequestProperty("User-Agent","NetFox"); u0@i3Po
String sProperty = "bytes="+nStartPos+"-"; ZE*m;
httpConnection.setRequestProperty("RANGE",sProperty); PmGW\E[ni
Utility.log(sProperty); z|V5/"
a3<.F&c+c
Q6G-`&5
InputStream input = httpConnection.getInputStream(); 2h6<'2'o1
//logResponseHead(httpConnection); @L-3&~=
O,kzU,zOs
ho7L@NR
byte[] b = new byte[1024]; {i7Wp$ug
int nRead; L.uX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ByrK|lVM0
{ \V#2K><
nStartPos += fileAccessI.write(b,0,nRead); |nN{XjNfP5
//if(nThreadID == 1) rR4_=S<Mi:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y0d a8sd)
} E2s lpo
]mN'Qoc
5;5DEMe
Utility.log("Thread " + nThreadID + " is over!"); ]i-peBxw
bDownOver = true; `;ofQz4
//nPos = fileAccessI.write (b,0,nRead); p. eq N
} GN4'LU
catch(Exception e){e.printStackTrace ();} 3f2%+2Zjt,
} A?V[/
} ERO'{nT&
swBgV,;
:3s5{s
//打印回应的头信息 cViEvS r
public void logResponseHead(HttpURLConnection con) Vs-])Q?7J
{ w~NQAHAvo
for(int i=1;;i++) =""z!%j
{ P9)E1]Dc$
String header=con.getHeaderFieldKey(i); fAu^eS%>7
if(header!=null) "eq{_4dL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :@:i*2=
Utility.log(header+" : "+con.getHeaderField(header)); brA\Fp^
else lw4#xH-?
break; fWx %?J
} CfguL@tR.
} :esHtkyML
d;3/Vr$t=
BULf@8~(
public void splitterStop() 9+G.86Iky
{ I+,~pmn:
bStop = true; v`"z
} &@O]'
[X'XxYbZ
qn VxP&
} 7cGc`7
=/Ob kVYf
`.dX@<
/* DD3.el}6a
**FileAccess.java wo($7'.@
*//文件访问(定位，写) N02X*NC
package NetFox; 0j^QY6
import java.io.*; :Yi1#
@5!Mr5;
M]O _L
public class FileAccessI implements Serializable{ O,`#h*{N
9E/{HNkf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t6GL/M4
RandomAccessFile oSavedFile; )[d?&GK
long nPos; gOpi>
v+. n9
*9#6N2J$M
public FileAccessI() throws IOException 4l/hh|3@
{ ^gb3DNV~y
this("",0); G_GV
} [?3]+xr:
uD=i-IHT
(yjx+K_[
public FileAccessI(String sName,long nPos) throws IOException &b[.bf
{ L|hdV\
oSavedFile = new RandomAccessFile(sName,"rw"); H ?Vo#/
this.nPos = nPos; F-L!o8o
oSavedFile.seek(nPos); I}djDtJ
} SV2DvrIR
,(H`E?m1w4
J*Dt\[X
public synchronized int write(byte[] b,int nStart,int nLen) :6k8\{^9"D
{ RRW/.y
int n = -1; u@j]U|FpY
try{ Aofk<O!M
oSavedFile.write(b,nStart,nLen); ftS^|%p
n = nLen; @>Y.s6a
} : +Na8\d
catch(IOException e) $#3O:aW
{ {}r#s>
e.printStackTrace (); : GVyY]qBU
} J!O{.v
a$0,T_wD
dNH6%1(s]0
return n; VRuY8<E
} bC_qoI<
@>>8CU^~
:@BAiKa[wa
} G(g`>' m
|mx)W}
97/"5i9
/* =:)p\{B
**SiteInfoBean.java }HO3D.HE^
*/ 4R 9lA
package NetFox; `/W6,]
v|IPus|>
_Xs(3V@'}
public class SiteInfoBean { Q"o* \I
Z>0a?=1[
}BTK+Tk8
private String sSiteURL; //Site's URL j#}wg`P"A
private String sFilePath; //Saved File's Path W6~aL\[
private String sFileName; //Saved File's Name ['<Q402:.
private int nSplitter; //Count of Splited Downloading File 5<Ly^Na:
W9i}w&
]i$<<u
public SiteInfoBean() $ z4JUr!m
{//nSplitter的缺省值为5 5k%GjT
//default value of nSplitter is 5 U/hf?T;
this("","","",5); ~.FeLWP
} UH8q:jOi
S511}KPbm/
K]~! =j)v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9'1XZpM1
{ VFmG\
sSiteURL= sURL; u'Od~x^z
sFilePath = sPath; |6]2XW
sFileName = sName; bl8zcpdL
this.nSplitter = nSpiltter; +JyD W%a:L
Uq}FrK}
#6fQ$x(F#j
} $&fP%p
A_h|f5
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public String getSSiteURL() ){-Tt`0(u
{ q mJ#cmN
return sSiteURL; c@eQSy
} j ^Tb=
8IeE7
uPe&i5YR
public void setSSiteURL(String value) p(B^](?
{ ,, 8hU7P
sSiteURL = value; BM~>=emc
} Sw1z^`
Q7 4Q|r7
/Bt+Ov3k
public String getSFilePath() )Y@E5Tuk>
{ wwvS05=[T
return sFilePath; ,@\$PyJ
} bD2):U*Fzo
%S`ygc}|
hg2a,EU\Z
public void setSFilePath(String value) ILN Yh3
{ sJI" m'r=Z
sFilePath = value; aXv[~
} ec8iZ8h8
M0jC:*D`"
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public String getSFileName() )9pRT dT
{ oouhP1py,
return sFileName; +69[06F
} `G@(Z:]f,t
QPD[uJ(I
`6No6.\J
public void setSFileName(String value) 8QJ^@|7
{ "c9T4=]&t
sFileName = value; !7rk>YrY
} ES4[@RX
j1Ns|oph1
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public int getNSplitter() O:%,.??<%
{ q0m>NA
return nSplitter; b] EC+.
} {)CN.z:O
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9Sb[5_Q
public void setNSplitter(int nCount) e) \PW1b
{ n<)gS7
nSplitter = nCount; yQ [n7du
} )yl;i
} ln1QY"g
M?gc&2Y
G7qB
/* pdw;SIoC
**Utility.java |//D|-2
*/ vkjHh.
package NetFox; B4#XQ-
P&snIJ
dED&-e#
public class Utility { vY"i^a`f
'NAC4to;;
\yE*nZ
public Utility() &6@#W]_
{ zObrp
#0*oj/
JS!`eO/8
} -"CXBKHb
E,}(jAq7
//线程睡眠 %a=^T?8
public static void sleep(int nSecond) n>XfXt =
{ *SmR|Qy
try{ XU*4MU^'
Thread.sleep(nSecond); eZ G#op
} [uLpm*7
catch(Exception e) i)1013b
{ -V F*h.'
e.printStackTrace (); W#bOx0
} N51e.;
} xf7_|l
nB9(y4
//日志 }8LTYn
public static void log(String sMsg) Z.%0yS_T
{ P+Q}bTb8
System.err.println(sMsg); OpLo[Y\
} lJJ`aYDp
!+)5?o
v.!e1ke8D*
public static void log(int sMsg) Q/%]%d
{ 0s72BcP
System.err.println(sMsg); V|hr9
} -Q MO*PY
} GlOSCJZ
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QFg{.F?3q>
/* <HfmNhI85(
**TestMethod.java <-(n48
*/ \sEH)$R'
package NetFox; 6 =H]p1p~O
L;i(@tp|v
IJk<1T7:(W
public class TestMethod { 2uzy]faM
>$:_M*5
nJ|M
public TestMethod() d "%6S*dL
{ ///xx/weblogic60b2_win.exe ]j+J^g
try{ ,382O$C
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0x2[*pJ|IW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1EHL8@.M
SiteFileFetch fileFetch = new SiteFileFetch(bean); M`49ydh&
fileFetch.start(); *3A)s O
} 6R|^IPOGp
catch(Exception e){e.printStackTrace ();} 5_[we1$P
S7h?tR*u
FT Ytf4t
} % pQi}x
43s8a
)ZMR4U$+v
public static void main(String[] args) aflBDo1c
{ jAxrU
new TestMethod(); pnp)- a*7
} ZkmYpi[
} *q*$%H
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