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)); A-&'/IHR"B
} )K.'sX{B
for(int i=0;i<nEndPos.length-1;i++) JO3x#1~;_
{ PnUYL.v
nEndPos = nStartPos[i+1]; 5DI&pR1eZ
} R4#56#d<
nEndPos[nEndPos.length-1] = nFileLength; 5x2m]u
} 2C@ui728
} <Z>p1S
x%Fy1.
WZ A8D0[
//启动子线程 'yw7|i2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )B!64'|M
for(int i=0;i<nStartPos.length;i++) j><8V Qx
{ 1v?|n8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M[= #%U3*N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M>yt\qbkA
nStartPos,nEndPos,i); <hv {,1p-r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ru5T0w";V
fileSplitterFetch.start(); Mb1K:U
} C-TATH%f^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t0"2Si
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ds#om2)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (QFu``ae+
nEndPos = " + nFileLength); jgyXb5GY
// fileSplitterFetch[nPos.length-1].start(); {SOy-
rHMr8,J;
u&Lp
//等待子线程结束 ?j:g.a+U
//int count = 0; )Bb:?!EuEH
//是否结束while循环 s6YnNJ,SK
boolean breakWhile = false; "Xz[|Xl
*;0Ods+IcY
=9;2(<A
while(!bStop) <0M2qt8
{ VmbfwHRWb
write_nPos(); 3yXSv1
Utility.sleep(500); #$?!P1
breakWhile = true; Es^=&2''
nu<kx
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for(int i=0;i<nStartPos.length;i++) _enS_R
{ 9N*!C{VW
if(!fileSplitterFetch.bDownOver) Y *?hA'
{ +)06*"I
breakWhile = false; &~MM\,KML
break; /f Ui2[y
} ysDGF@wZC
} 1(4}rB3
if(breakWhile) l2ww3)Z
break; QZ?%xN(4
%'3Y?d
J*zm*~8\
//count++; ])vWvNx
//if(count>4) dZ;rn!dg>
// siteStop(); TMAart;<
} RkTO5XO
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;>jLRx<KC
System.err.println("文件下载结束！"); tFrNnbmlQ
} %;-r->
catch(Exception e){e.printStackTrace ();} CWx_9b zk
} yGZsPQIaV
ps&p|
ELa:yIl0
//获得文件长度 t}m"rMbt
public long getFileSize() y|h:{<
{ "IMq +
int nFileLength = -1; 1yT\|2ARZ%
try{ ki<4G
URL url = new URL(siteInfoBean.getSSiteURL()); lDF26<<\`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <52)
httpConnection.setRequestProperty("User-Agent","NetFox"); _]q%Hve
cjyb:gAO
GGF;4
int responseCode=httpConnection.getResponseCode(); o)SA^5
if(responseCode>=400) +~l`rJ
{ oV,lEXz
processErrorCode(responseCode); Ua\<oD79]
return -2; //-2 represent access is error oaMh5FPy
} O od?ifA
(rB?@:zN
x^u[L$
String sHeader; eW.[M?,
%o4HCzId<
!dZpV~g0
for(int i=1;;i++) @$] CC1Y
{ 5l,Q=V^@l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]~J.YX9ST
//Utility.log(in.readLine()); [&H?--I
sHeader=httpConnection.getHeaderFieldKey(i); u8sK~1CPf
if(sHeader!=null) ns;nle|m
{ q A?j-H
if(sHeader.equals("Content-Length")) =[x @BzH
{ ptvM>zw'~g
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); = }6l.9
break; /'WVRa
} +:m'a5Dm
} ;VIW/
else oNa*|CSE>
break; p&<X&D
} 8j%hxAV$
} `|d&ta[{
catch(IOException e){e.printStackTrace ();} aVbv.>
catch(Exception e){e.printStackTrace ();} Ii4lwZnz
=h/0k y
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Utility.log(nFileLength); "H!2{l{
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8jxs%N,aI
return nFileLength; ({l!'>?
} fsVQZ$h73
UB&)U\hn
d/3 k3HdL
//保存下载信息（文件指针位置） km+}./@
private void write_nPos() >xa k
{ *[?DnF+
try{ 2gC.Z:}
output = new DataOutputStream(new FileOutputStream(tmpFile)); +""8aA
output.writeInt(nStartPos.length); yg-uL48q
for(int i=0;i<nStartPos.length;i++) 2~BId&]
{ $xU5vCwAo
// output.writeLong(nPos); %}%vey
output.writeLong(fileSplitterFetch.nStartPos); |[]"{Eo"}
output.writeLong(fileSplitterFetch.nEndPos); l<l6Ey(
} *=O~TY<](
output.close(); kb>/R/,9
} >kJEa8
catch(IOException e){e.printStackTrace ();} U]h5Q.<SG
catch(Exception e){e.printStackTrace ();} Tfba3+V
} jSyF]$"
_Xn[G>1
(!^(74
//读取保存的下载信息（文件指针位置） MxXu&.|_
private void read_nPos() ]c \gUU
{ !pNY`sw}
try{ 5YG?m{hyn_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [|\JIr=of5
int nCount = input.readInt(); {t;{={$
nStartPos = new long[nCount]; !a[1rQH
nEndPos = new long[nCount]; h6dVT9
for(int i=0;i<nStartPos.length;i++) liUrw7,
{ M8,W|eTM
nStartPos = input.readLong(); ttwfWfX
nEndPos = input.readLong(); aiKZ$KLC
} W]UGo,
input.close(); 4ZK8Y[]Lv
} v_gQCS
catch(IOException e){e.printStackTrace ();} i7fQj, q
catch(Exception e){e.printStackTrace ();} TuBl9 p'6
} ,\|W,N}~
W:7oGZ>4
EEaf/D/jt
private void processErrorCode(int nErrorCode) }D7q)_g=
{ C#<:x!
System.err.println("Error Code : " + nErrorCode); 'y [eH
} IQS:tL/
Ew=8"V`C
_d'x6$Jg
//停止文件下载 \S)\~>.`y!
public void siteStop() B?nQUIb:
{ S3[rv
bStop = true; t&SC>8M<
for(int i=0;i<nStartPos.length;i++) .O{2]e$
fileSplitterFetch.splitterStop(); T<|B1jA
g3%Xh0007{
af61!?K
} u6AReL'f
} $/aZ/O)F
//负责部分文件的抓取 4eym$UWw
**FileSplitterFetch.java x?:[:Hf
*/ t%e}'?#^
package NetFox; 1Z?en
(KDUX t.
c|lo%[]R!
import java.io.*; #7IM#tc@
import java.net.*; Fg)Iw<7_2
fQ5VRpWGn
kzG mDi
public class FileSplitterFetch extends Thread { )z/+!y
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#Mt'y8|}$
String sURL; //File URL 'ao<gTUbu
long nStartPos; //File Snippet Start Position sv0)sL
long nEndPos; //File Snippet End Position \`\& G-\
int nThreadID; //Thread's ID {)j3Pn
boolean bDownOver = false; //Downing is over %O`e!p
boolean bStop = false; //Stop identical sr+* q6W
FileAccessI fileAccessI = null; //File Access interface O(8Px
tr6<89e(o
,y}?Z8?63
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [R[]&\W
{ =7@N'xX
this.sURL = sURL; 5o 4\Jwt
this.nStartPos = nStart; ;Bk?,g
this.nEndPos = nEnd; luYkC@I@a
nThreadID = id; .5*h']iFr1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j:# wt70
} ?El8:zt?|
;*^2,_
YIv!\`^ \
public void run() SFVOof#s
{ 45` i
while(nStartPos < nEndPos && !bStop) .UF](
{ @:u>
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T 22tZp
try{ FES_:?.0
URL url = new URL(sURL); v#1}( hb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m~cz
httpConnection.setRequestProperty("User-Agent","NetFox"); 5+*MqO>
String sProperty = "bytes="+nStartPos+"-"; o$]wd*+
httpConnection.setRequestProperty("RANGE",sProperty); (_h<<`@B
Utility.log(sProperty); C7#ji"t
b^[Ab:`}[V
~.99H
InputStream input = httpConnection.getInputStream(); [IT*>;b+?
//logResponseHead(httpConnection); u;f${Wn'3
22aS <@}
.?T,>#R
byte[] b = new byte[1024]; 6)i4&
int nRead; c++GnQc.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N `-\'h
{ npC:SrI%
nStartPos += fileAccessI.write(b,0,nRead); "mlVs/nsyG
//if(nThreadID == 1) E9e|+$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8aDhHXI
} s8L=:hiSf)
32nB9[l
<d89eV+
Utility.log("Thread " + nThreadID + " is over!"); ~9%L)nC2'
bDownOver = true; _m.u@+g
//nPos = fileAccessI.write (b,0,nRead); DX>Yf}
} VfWU-lJ
catch(Exception e){e.printStackTrace ();} /J''`Tf
} 0c6b_%Rd
} KE>|,Ur
v_M-:e3`
WzD=Ol
//打印回应的头信息 1iNq|~
public void logResponseHead(HttpURLConnection con) Vwxb6,}Z
{ P2la/jN
for(int i=1;;i++) bMe/jQuL.$
{ &QHZ]2%U
String header=con.getHeaderFieldKey(i); gR7in!8
if(header!=null) +9LIpU&5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HK_Vk\e
Utility.log(header+" : "+con.getHeaderField(header)); ^n Gj 7b
else Hw"LoVh
break; r<< ]41
} t&5N{C:
} O5X@'.#rU
8EbJ5wu/%S
?|4Y(0N
public void splitterStop() %gBulvg
{ w[ )97d
bStop = true; e_U1}{=t
} N@}5Fnk-
90g=&O5@O
<}Hfu-PLo
} 1jHugss9|
p>Z18
qPal'c0
/* d\c?sYLv
**FileAccess.java 3|++2Z{},
*//文件访问(定位，写) |E]`rfr
package NetFox; 73C7g< Mx
import java.io.*; Fsdp"X.
c+dmA(JC
m2sf]-?Y
public class FileAccessI implements Serializable{ ^@91BY
%?2:1o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Dx1f<A1
RandomAccessFile oSavedFile; V LXU
long nPos; !H)Cua)
]2zzY::Sd=
d2\#Zlu<
public FileAccessI() throws IOException <GdQ""X
{ )By#({O
this("",0); L0^rw|Z%'
} Nw3K@Ge
[hhPkJf|f
9nGS"E l{
public FileAccessI(String sName,long nPos) throws IOException PiL[&_8g
{ Hl|EySno
oSavedFile = new RandomAccessFile(sName,"rw"); -F->l5
this.nPos = nPos; ta;q{3fe
oSavedFile.seek(nPos); GkU]>8E'"
} :o37 V!
+cXdF
1uwzo9Yg
public synchronized int write(byte[] b,int nStart,int nLen) QV%,s!_b
{ 1r:i'cWh
int n = -1; P<E!ix
try{ =|j~*6Hd
oSavedFile.write(b,nStart,nLen); ta
n = nLen; b^s>yN
} tNbL)
catch(IOException e) A_pcv7=@
{ 0?80V'
e.printStackTrace (); ;NoD4*
} fkHCfcU
ov xX.hO
x<=<Lx0B;
return n; Lb=4\ _
} @Jh;YDr`A
]DJ]L=T7
5f}GV0=n
} |V dr/'
k$d+w][
n/ m7+=]v
/* 7eU|iDYo
**SiteInfoBean.java ^630%YO
*/ (?ofL|Cg(
package NetFox; e$Npo<u
vyhxS.[9
>|W\8dTQ
public class SiteInfoBean { .ng:Z7
$`'%1;y@
Ld4Jp`Zg
private String sSiteURL; //Site's URL b%_[\((
private String sFilePath; //Saved File's Path +Rq7m]
private String sFileName; //Saved File's Name "k>;K,:
private int nSplitter; //Count of Splited Downloading File X/AA8QV o
vVfIe5+OP
,b${3*PPQ
public SiteInfoBean() n&fV^ x
{//nSplitter的缺省值为5 <&m `)FJ
//default value of nSplitter is 5 HUWCCVn&
this("","","",5); +cf.In,{
} <8sy*A?0z
Su>UXuNdE#
7nl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;=i$0w9W
{ au?5^u\
sSiteURL= sURL; U/j+\Kc~
sFilePath = sPath; dk@j!-q^
sFileName = sName; @FLa i
this.nSplitter = nSpiltter; ];U}'&
JQO%-=t
) mG
} Xxmvg.Nl
w=}R'O;k
PvkHlb^x%
public String getSSiteURL() 4+2hj*I
{ G ]JWd
return sSiteURL; IA(+}V
} A1kqWhg\
l ]CnLqf&
jHx)q|2\
public void setSSiteURL(String value) ?S0gazZm
{ y^tp^
sSiteURL = value; \?K>~{)
} 5Vu@gRk_
a"pejW`m
ffibS0aM
public String getSFilePath() `7o(CcF6H
{ k_A 9gj1
return sFilePath; 0o*
} !vwx0
j|c6BdROl
R3!3TJ
public void setSFilePath(String value) &-B&s.,kj
{ Q!(qL[o
sFilePath = value; (.J8Q
} m=e#1Hs
z<Y >phc
>^V3Z{;
public String getSFileName() +f]\>{o4
{ 7nOn^f D
return sFileName; AOVoOd+6
} A_}%YHb
JzZ9ua
B_uAa5'
public void setSFileName(String value) oHj64fE9
{ U.0bbr
sFileName = value; \[5mBuk
} +/Vi"
>x6$F*:W}
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public int getNSplitter() a8[Q1Fa4|
{ g$eZT{{W
return nSplitter; Z+J;nl
} =S|^pN
Kj`sq":Je0
o7#Mr`6H
public void setNSplitter(int nCount) S&w(H'4N
{ 8QaF(?
nSplitter = nCount; AXOR<Ns`
} @[] A&)B
} cc|"^-j-7
G?&T0
e)x;3r"j
/* jpW(w($XL
**Utility.java t 9Dr%#
*/ 76M`{m
package NetFox; }5qjGD
r")zR,
;th]/ G
public class Utility { q*kieqG
{Vj25Gt
[AHZOA
public Utility() TV&4m5
{ {cF>,T
`9yR,Xk=l
\mt>R[
} X/!37
7h3JH
//线程睡眠 FeM,$&G:
public static void sleep(int nSecond) =P"Sm r
{ Z" !+p{u
try{ 68v59)0U
Thread.sleep(nSecond); c6NCy s
} >|e>=
catch(Exception e) 9v2(cpZ
{ [Y^1}E*
e.printStackTrace (); <fLk\ =
} I$7TnMug
} 6qgII~F'
D;l)&"|r?
//日志 LN?b6s75U
public static void log(String sMsg) ^MZdht
{ 9+sOSz~ P
System.err.println(sMsg); k-M-=VvA
} b[I;6HW
2r]!$ hto
<Gr775"
public static void log(int sMsg) }nW)+
{ ,UD,)ZPf[
System.err.println(sMsg); ecI[lB
} E*t0ia8
} &_!g|-
2\,vq R
.C2.j[>
/* #(`@D7S"
**TestMethod.java B?xu!B,
*/ L,F )l2
package NetFox; = +uUWJ&1G
VK)K#!O8
5_mb+A n,
public class TestMethod { >iCkvQ
Qs*6wF
rl,6ru
public TestMethod() AjQ^ {P
{ ///xx/weblogic60b2_win.exe AwKxt'()^
try{ h4GR:`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Bkn- OG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p5KM(N6f
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ass8c]H@
fileFetch.start(); FH'jP`
} .+H8c.
catch(Exception e){e.printStackTrace ();} kd9GHN;7
gJVakR&
#@m*yJg<
} :95wHmk
I54O9Aoy
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public static void main(String[] args) AUnRr+o
{ #_+T@|r
new TestMethod(); sq_N!
} eXaa'bTx
} / 4K*iq
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