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)); }R`}Ey|{
} '8b=4mrbH
for(int i=0;i<nEndPos.length-1;i++) _#w5hXcu
{ a]4|XJ_
nEndPos = nStartPos[i+1]; j2jUrl
} uKo4nXVtp
nEndPos[nEndPos.length-1] = nFileLength; mWuhXY^Q
} ;(IAhWE?7
} =h}PL22
'>>@I~<\
n;k B_i*l
//启动子线程 I bE Nq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w^/"j_p@
for(int i=0;i<nStartPos.length;i++) ;h#CT#R2
{ $'bb)@_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 94.M8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qGgdWDn`
nStartPos,nEndPos,i); 8\[qR_LV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _RX*Ps=
fileSplitterFetch.start(); D66!C{
} =A;79@bY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j4h?"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ; .hTfxE0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]v.Yt/&C{
nEndPos = " + nFileLength); /!-ypIY
// fileSplitterFetch[nPos.length-1].start(); sE0,b
O9Yk5b;
? \NT'CG
//等待子线程结束 E9j(%kQ2
//int count = 0; j{P3o<l&`
//是否结束while循环 g=s2t"&
boolean breakWhile = false; X($@E!|
!}HT&N8[r
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while(!bStop) v9Ez0 :)
{ 0*o=JM]
write_nPos(); 'Y5=A!*@tf
Utility.sleep(500); a0Q\]S
breakWhile = true; CvqUaHW@
KQ.cd]6
IFWP&20
for(int i=0;i<nStartPos.length;i++) U6 H@l#
{ O9F#gO|!
if(!fileSplitterFetch.bDownOver) Y+"Gx;F>
{ 66cPoG
breakWhile = false; }fz;La:b
break; ="]y^&(L(
} 9R4q^tGR\
} .vXe}%
if(breakWhile) 2|LkCu)~,"
break; FBrJVaF
)F:UkS
6}PoBhgSg-
//count++; )>a^%V9
//if(count>4) 8wA'a'V.
// siteStop(); sg,9{R ^
} 3<HPZWc
9_pOV%Qs
~ph>?xuw
System.err.println("文件下载结束！"); |C;*GeyS;J
} ow,=M%x"0
catch(Exception e){e.printStackTrace ();} +#ANc;2g
} ~kPZh1n`
$-f(.S
j~Ubpf
//获得文件长度 3/2G~$C
public long getFileSize() r$-]NYPi
{ 6-uB[$ko
int nFileLength = -1; F% K}&3
try{ o<%s\n
URL url = new URL(siteInfoBean.getSSiteURL()); sxQMfbN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S31+ j:"
httpConnection.setRequestProperty("User-Agent","NetFox"); )rv<"
84maX'
I`EgR?5 `
int responseCode=httpConnection.getResponseCode(); PiwI.c
if(responseCode>=400) %ck/ Z
{ <2 S?QgR,
processErrorCode(responseCode); 8BwJWxBQ
return -2; //-2 represent access is error \+sP<'~M
} :KJZo,\
N^K@$bs4^
G7H'OB &
String sHeader; rfxLCiV
Hf$LWPL)lM
KmRxbf
for(int i=1;;i++) JZB@K6 ~dO
{ d!]_n|B@9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X7& ^"|:
//Utility.log(in.readLine()); Y/< ],1U
sHeader=httpConnection.getHeaderFieldKey(i); ?TVR{e:
if(sHeader!=null) /|{~GD +A&
{ z[ ml;?
if(sHeader.equals("Content-Length")) $qj||zA
{ Md,KW#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o9uir"=
break; (.B+U'6
} Ndr4e?Xa,
} {H%1sI
else ;]Bkw6o
break; ~b.e9FhdA
} S4BU!
} Nb@zn0A(;
catch(IOException e){e.printStackTrace ();} %QrpFE5V5
catch(Exception e){e.printStackTrace ();} au 5qbP
9q!./)
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Utility.log(nFileLength); ]pP [0S
9~$'?
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return nFileLength; )s4a<Sc]
} z gDc=
knJoVo]
Ro|%pT
//保存下载信息（文件指针位置） 2DTBL:?`
private void write_nPos() ,,[pc
{ :IlJQ{=W
try{ )S6"I
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^J Y]w^u
output.writeInt(nStartPos.length); w(Hio-l=
for(int i=0;i<nStartPos.length;i++) 42mZ.,<
{ F[5\ x0
// output.writeLong(nPos); gT~Yn~~b
output.writeLong(fileSplitterFetch.nStartPos); ;nB.f.e`
output.writeLong(fileSplitterFetch.nEndPos); /DBldL7yi
} $q~:%pQv
output.close(); s>^$: wzu
} 1ti4 ZM
catch(IOException e){e.printStackTrace ();} 3A.T_mGCs
catch(Exception e){e.printStackTrace ();} 1W +QcK4k
} D/-$~u_o
L H`z '7&/
Td6"o&0A!
//读取保存的下载信息（文件指针位置） s5'So@L8
private void read_nPos() e[a?5,s2
{ :F`yAB3
try{ -<tfbaA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xK3}zN$T
int nCount = input.readInt(); 2{E"#}/
nStartPos = new long[nCount]; B> LL *
nEndPos = new long[nCount]; Ho;bgva
for(int i=0;i<nStartPos.length;i++) |}>;wZ[7
{ o7W1sD1O
nStartPos = input.readLong(); &.}Zj*BD
nEndPos = input.readLong(); CsND:m
} =fr_` "?k
input.close(); _<i*{;kR6
} #U j~F
catch(IOException e){e.printStackTrace ();} [10;Mg
catch(Exception e){e.printStackTrace ();} UI>?"b6 L
} 1]<wZV}.
`vFYeN;
gP?uLnzvi
private void processErrorCode(int nErrorCode) -O?}-6,_Z
{ `Mp-4)mn
System.err.println("Error Code : " + nErrorCode); z_LN*u
} &_N$S2
{)8!>K%G
]FLi^}ct
//停止文件下载 (NBq!;_2,x
public void siteStop() ?yq1\G)]
{ .s!qf!{V`
bStop = true; fudIUG.
for(int i=0;i<nStartPos.length;i++) o@&dd NO
fileSplitterFetch.splitterStop(); w_hGWpm
7FiQTS B:
Tp7slKc0p
} s;;"^5B.
} T$ )dc^
//负责部分文件的抓取 JBKCa 3
**FileSplitterFetch.java ZRd,V~iz
*/ ZOK,P
package NetFox; Dqw?3 KB
S EeDq/h
eQRY xx{
import java.io.*; Mh+ym]6\(k
import java.net.*; kr|u ||
>$yqx1=jW
DVWqrK}q
public class FileSplitterFetch extends Thread { CI )89`
k7gm)}RKcu
9a*}&fL[
String sURL; //File URL 855JAf
long nStartPos; //File Snippet Start Position s@ ~Y!A
long nEndPos; //File Snippet End Position '!%Zf;Fjr
int nThreadID; //Thread's ID uzx?U3.\
boolean bDownOver = false; //Downing is over hZobFf
boolean bStop = false; //Stop identical &7YTz3aj
FileAccessI fileAccessI = null; //File Access interface C&QT-|
[0(+E2/:2
o=1M<dL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6?3f+=e"~!
{ =V@5W[bV
this.sURL = sURL; `;9Z?]}`
this.nStartPos = nStart; 1%nE
this.nEndPos = nEnd; q)ns ui(
nThreadID = id; jd]YKaI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @,Iyn<v{B
} DhAQ|SdCf
A80r@)i
tX$v)O|
public void run() |Ts|>"F'
{ n!r<\4I
while(nStartPos < nEndPos && !bStop) _U"9#<
{ jx3J$5
cBO.96ZHE
&pCNOHi|
try{ 6tPgFa#N
URL url = new URL(sURL); XPhC*r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y|NANjEAfm
httpConnection.setRequestProperty("User-Agent","NetFox"); s 9Y'MQo*
String sProperty = "bytes="+nStartPos+"-"; /2!Wy6p
httpConnection.setRequestProperty("RANGE",sProperty); o-))R| ~z
Utility.log(sProperty); 8pQx6QE
OUd&fUmH
QD6in>+B@
InputStream input = httpConnection.getInputStream(); f+/AD
//logResponseHead(httpConnection); |Mj2lZS
R3;,EL{H&
FG^Jh5
byte[] b = new byte[1024]; fR&;E
int nRead; 6,707h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '9+JaB
{ `n*e8T
nStartPos += fileAccessI.write(b,0,nRead); <Oi65O_X
//if(nThreadID == 1) %q~YJ*\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e-Xr^@M*Q
} =peodj^
fr\"MP
^4WNP
Utility.log("Thread " + nThreadID + " is over!"); {!lC$SlJ
bDownOver = true; w$X"E*~>8
//nPos = fileAccessI.write (b,0,nRead); DcO$&)Eb
} }-ly'4=l
catch(Exception e){e.printStackTrace ();} L*Gk1'
} wN|;_~h2
} T=EHue$
oV)#s!
fL #e4
//打印回应的头信息 |#_F
public void logResponseHead(HttpURLConnection con) 'UYxVh9D
{ %yjz@
for(int i=1;;i++) ^ucmScl
{ d-zNvbU"
String header=con.getHeaderFieldKey(i); *kmD/J
if(header!=null) \i*QKV<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H+ P&} 3
Utility.log(header+" : "+con.getHeaderField(header)); x:7"/H|
else Y+,ii$Ce~
break; cN#c25S>
} &%@b;)]J
} B#>7;xy>
qHZ!~Kq,"'
^ZxT0oaL
public void splitterStop() r9nyEzk
{ " vW4"R6
bStop = true; LFzL{rny!U
} -W/Lg5eK
b9F:X
i#&iT P`
} r%craf
I`$"6 Xy
g[D(]t\#x
/* Y<4%4>a
**FileAccess.java -x~4@~
*//文件访问(定位，写) WE-cq1)
package NetFox; s?fO)7ly
import java.io.*; u<VR;p:y
k10g %K4g
/IO<TF(X
public class FileAccessI implements Serializable{ SBf8Ipe
\E(Negt7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ` XvuyH
RandomAccessFile oSavedFile; n=z=%T6
long nPos; Ft<6`C
%4=r .9
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public FileAccessI() throws IOException \aEarIX#*
{ n A<#A
this("",0); F}f/cG<X
} c'wxCqnE
F*}.0SQ
.T>^bLuFy
public FileAccessI(String sName,long nPos) throws IOException 8h.Dc&V
{ ^$N}[1
oSavedFile = new RandomAccessFile(sName,"rw"); U,tl)(!@Q-
this.nPos = nPos; W Ai91K@
oSavedFile.seek(nPos); L@|xpq
} Y"n$d0%
1edeV48{:
j3Sz+kOf,
public synchronized int write(byte[] b,int nStart,int nLen) 0SHF 8kek
{ z]twh&^1L
int n = -1; TtWE:xE
try{ dcd9AW=
oSavedFile.write(b,nStart,nLen); +Fk]hCL
n = nLen; {o."T/?d'
} iI]E%H}
catch(IOException e) I+!?~]AUuq
{ @VzD>?)
e.printStackTrace (); ~S85+OJ;M
} pzQWr*5a
kKFhbHUZa
8mmHefZ}2!
return n; yUyx&Y/
} WZ A8D0[
!wU~;sL8C3
\#hp,XV>
} )B!64'|M
F?!X<N{
1.U9EuI
/* 1v?|n8
**SiteInfoBean.java @ptE&m
*/ S^,q{x*T
package NetFox; 2Hp<(
e8Y;~OAj[
o6v'`p'
public class SiteInfoBean { #cAX9LV
evLZ<|
0dKv%X#\
private String sSiteURL; //Site's URL 7`G FtX}
private String sFilePath; //Saved File's Path t0"2Si
private String sFileName; //Saved File's Name b~u53
private int nSplitter; //Count of Splited Downloading File Qp5YS
j1sgvh]D
[b?[LK}.
public SiteInfoBean() }jI=*
{//nSplitter的缺省值为5 rIhe}1
//default value of nSplitter is 5 H6vO}pq)r
this("","","",5); 6+iZJgwAy
} k^:+Pp
2Sha&Z*CE
3c|u2Pl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P'Gf7sQt7
{ M,R**z
sSiteURL= sURL; N+#lS7
sFilePath = sPath; YM`I&!n
sFileName = sName; 5ieF8F%
this.nSplitter = nSpiltter; OngUZMgdb
^rX5C2}G\D
Yo^9Y@WDW
} fhp+Ep!0Y
VmbfwHRWb
b;~?a#Z}
public String getSSiteURL() +p\+15
{ #$?!P1
return sSiteURL; vyXL F'L
} 7A6:*
H2iC? cSR
7K`Z<v&*
public void setSSiteURL(String value) _enS_R
{ gc"A Tc
sSiteURL = value; ebTwU]Nb
} UVlXDebl
6z3`*B
vkK8D#K
public String getSFilePath() *`WD/fG
{ :%2uZ/cG(
return sFilePath; >713H!uj
} 62Q`&n6
~ ~U,
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public void setSFilePath(String value) Y2&hf6BE
{ } >zl
sFilePath = value; FC&841F
} }u&,;]
8oxYgj&~X
ig}H7U2q@
public String getSFileName() _2Hehw
{ YX,xC-37y
return sFileName; mzH3Q564
} U_oei3QP
CeD(!1VG
v;$cx*?
public void setSFileName(String value) ;>jLRx<KC
{ #_9Jam%M
sFileName = value; [qHtN.
} 71wtO
u[b0MNE~
f)9{D[InM^
public int getNSplitter() c[zaYcbl
{ y-R:-K XH=
return nSplitter; wVac6q
} 'M=c-{f~
&C&?kS(
&|#z" E^-
public void setNSplitter(int nCount) 34s>hm=0.
{ d.:.f_|
nSplitter = nCount; a$2WL g,
} 3+tr_psH
} m`B.3
US2Tdmy@05
&?(472<f**
/* daN#6e4Z+;
**Utility.java NU |vtD
*/ I?#B_R#
package NetFox; DFN
EhK~S(r^
.N~YVul[a*
public class Utility { 6SVh6o@]
Ps=<@,dks
)sBbmct_S
public Utility() :j[a X7Sq2
{ c,FhI~>R
D4;6}gRC
l>{+X )
} (rB?@:zN
OJTEvb6nPg
//线程睡眠 q%\rj?U_
public static void sleep(int nSecond) eW.[M?,
{ {q^?Rw
try{ \rPT7\ZA
Thread.sleep(nSecond); _^Yav.A=
} y - Ge"mY
catch(Exception e) _;8+L\
{ o:nh3K/YJ
e.printStackTrace (); fNNik7
} vgbk {
} 6,:`esl
X0+M|8:
//日志 }\wTV*n`X
public static void log(String sMsg) :j4i(qcF
{ q A?j-H
System.err.println(sMsg); 8^)K|+_'m
} O}cg1Q8p
y jQpdO
:^*9Eb
public static void log(int sMsg) M-+pYv#&P
{ Zg2F%f$Y
System.err.println(sMsg); /Q*cyLv
} m~U2L
} eHQ3K#M#
oNa*|CSE>
& GM&,
/* vddh 2G
**TestMethod.java BBUXoz
*/ i=DoK{`L
package NetFox; 97~*Z|#<+
Ii4lwZnz
3|g]2|~w@h
public class TestMethod { mbCY\vEl
tW7*(D
{nl4(2$
public TestMethod() =`y.L5
{ ///xx/weblogic60b2_win.exe *3r{s'm
try{ a eo/4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); BR[f{)a5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6yRxb(
SiteFileFetch fileFetch = new SiteFileFetch(bean); W$_@9W(Bl
fileFetch.start(); Tx!c}
} i[x;k;m2q
catch(Exception e){e.printStackTrace ();} i~04P
km+}./@
Ls~F4ar$/
} EPMdR66
oN/T>&d
8E9W\@\
public static void main(String[] args) +""8aA
{ @vcvte
new TestMethod(); Tl ?]K
} 2~BId&]
} 3cztMi
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