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)); "2'pS<|
} }QqmDK.
for(int i=0;i<nEndPos.length-1;i++) `fRp9o/
{ nrpxZA
nEndPos = nStartPos[i+1]; &m>sGCZ
} ?$#,h30
nEndPos[nEndPos.length-1] = nFileLength; (7qdrAeP
} #K3`$^0 s
} {yPiBu
/=bg(?nX
CI )89`
//启动子线程 k7gm)}RKcu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; DJmT]Q]o)
for(int i=0;i<nStartPos.length;i++) 0cwb^ffN
{ e5 ?;{H
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TEK]$%2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), eaxp(VX?oy
nStartPos,nEndPos,i); [*k25N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Iw<: k
fileSplitterFetch.start(); u#l@:p
} }RvP*i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @l:o0(!W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JPt=~e(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 18AKM
nEndPos = " + nFileLength); pUz;e#J|
// fileSplitterFetch[nPos.length-1].start(); RnX:T)+o
^atX/
cN5,\I.
//等待子线程结束 `bJ+r)+5
//int count = 0; bH-QF\>
//是否结束while循环 mQ@A3/=`
boolean breakWhile = false; .qcIl)3
R4V~+tnbG&
J(
while(!bStop) 'w8k*@cQ
{ I+?9}t
write_nPos(); )r)3.|wJm
Utility.sleep(500); z|o7k;raH
breakWhile = true; 9"=1 O
/7nircXj@
(Mk9##R#
for(int i=0;i<nStartPos.length;i++) S<f]Y4A&
{ 8<Y*@1*j
if(!fileSplitterFetch.bDownOver) ^11y8[[
{ `n*e8T
breakWhile = false; {*Ag[HS0u
break; |bwz
} o~vUqj?BA
} Qd %U(|
if(breakWhile) J 8z|ua
break; GI~JIXHTQ
X#bK.WN$
vqC!Ajm
//count++; 3N(5V;ti
//if(count>4) &DX&*Xq2
// siteStop(); \i*QKV<
} b"lzR[X,e
jf`QoK
S~~G0GiW
System.err.println("文件下载结束！"); _M;n.?H
} vn]e`O>y
catch(Exception e){e.printStackTrace ();} " vW4"R6
} Z%Kkh2-uh
M+7&kt0;
9hJlc
//获得文件长度 S,ENbP%0r
public long getFileSize() Lp|7s8?
{ 3Kx&+
int nFileLength = -1; u<VR;p:y
try{ iI!MF1
URL url = new URL(siteInfoBean.getSSiteURL()); v%ldg833l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &V`~ z e
httpConnection.setRequestProperty("User-Agent","NetFox"); nY>UYSv
6T?$m7c
S%^*h{9u"
int responseCode=httpConnection.getResponseCode(); m-<"`:+
if(responseCode>=400) n A<#A
{ ^=COgO]e
processErrorCode(responseCode); agbG)t0
return -2; //-2 represent access is error {RmN1'%
} dR9[K4`p/
ajy+%sXf=
4N!Eqw
String sHeader; 1edeV48{:
U.$7=Zl8t
m0}1P]dc
for(int i=1;;i++) 0qCx.<"p8#
{ [P3].#"]M=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }akF=/M
//Utility.log(in.readLine()); aqw;T\GI+~
sHeader=httpConnection.getHeaderFieldKey(i); )S8fFV
if(sHeader!=null) l_ES$%d
{ 1ti9FQ
if(sHeader.equals("Content-Length")) 2C@ui728
{ !.EDQ1k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [z2jR(+`U
break; x%Fy1.
} Wx`|u
} [T6MaP?
else 'yw7|i2
break; tO@n3"O
} ?V{AP&#M$x
} $`wo8A|)
catch(IOException e){e.printStackTrace ();} Iq[ d5)M4
catch(Exception e){e.printStackTrace ();} Rxf.@E
DNyU]+\L[l
>Oz~j>jL
Utility.log(nFileLength); >jBa
xoYaL
G@N-+
return nFileLength; a,YU)v^
} ru5T0w";V
] 'B4O1
L'@@ewA
//保存下载信息（文件指针位置） C-TATH%f^
private void write_nPos() K:JM*4W
{ A7hWAq
try{ zz7#gU
output = new DataOutputStream(new FileOutputStream(tmpFile)); ssx#\
output.writeInt(nStartPos.length); 0sR+@\
for(int i=0;i<nStartPos.length;i++) |EjMpRNE
{ ar%!h~
// output.writeLong(nPos); 2," (
output.writeLong(fileSplitterFetch.nStartPos); p%]ZG,
output.writeLong(fileSplitterFetch.nEndPos); Jg2*$gL;_
} m~<<ok_
output.close(); u&Lp
} (nUSgZz5
catch(IOException e){e.printStackTrace ();} S#|dmg;p
catch(Exception e){e.printStackTrace ();} )Bb:?!EuEH
} /hC'-6:]^
7_^JgA|Kk7
"Xz[|Xl
//读取保存的下载信息（文件指针位置） b-"kclK
private void read_nPos() -Z<V?SFOK
{ q qFN4AO
try{ Q$B\)9`v[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ? JliKFD%
int nCount = input.readInt(); T:G8xI1 P
nStartPos = new long[nCount]; 3yXSv1
nEndPos = new long[nCount]; sq;nUA=
for(int i=0;i<nStartPos.length;i++) 4r-CF#o
{ Es^=&2''
nStartPos = input.readLong(); Q\qI+F2?
nEndPos = input.readLong(); {*NM~yQ
} upc-Qvk
input.close(); #FwTV@
} h)o5j-M>4
catch(IOException e){e.printStackTrace ();} G,,7.%eib=
catch(Exception e){e.printStackTrace ();} a?NoNv)&
} iYR`|PJi
6z3`*B
}[O/u <Z
private void processErrorCode(int nErrorCode) c)q'" r
{ -NL=^O$G
System.err.println("Error Code : " + nErrorCode); y/\0qQ/
} )N}.n2Y8W
}n;.E&<[
tsys</E&
//停止文件下载 "NOll:5"(
public void siteStop() %'3Y?d
{ rWS],q=c
bStop = true; 8oxYgj&~X
for(int i=0;i<nStartPos.length;i++) ig}H7U2q@
fileSplitterFetch.splitterStop(); _2Hehw
YX,xC-37y
9'I$8Su
} RkTO5XO
} 7c>{og6
//负责部分文件的抓取 $>6Kn`UX
**FileSplitterFetch.java ll#_v^
*/ h#?)H7ft
package NetFox; G$7!/O%#_
hG!|ts
dxk~
import java.io.*; 1_MaaA;ow"
import java.net.*; ps&p|
*;!p#qL
c[zaYcbl
public class FileSplitterFetch extends Thread { t}m"rMbt
@S#Ls="G
wVac6q
String sURL; //File URL QKt+Orz
long nStartPos; //File Snippet Start Position =Dc9|WuHN
long nEndPos; //File Snippet End Position C[2LP$6*/
int nThreadID; //Thread's ID 1yT\|2ARZ%
boolean bDownOver = false; //Downing is over GW~ZmK
boolean bStop = false; //Stop identical w7"&\8a
FileAccessI fileAccessI = null; //File Access interface m14OPZ<3?-
-l i71.M
3uJ>:,~r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =cKrp'
{ T.B}k`$
this.sURL = sURL; *R8qnvE\()
this.nStartPos = nStart; M7. fz"M
this.nEndPos = nEnd; 1Uf8ef1,
nThreadID = id; m>8tA+K)+)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1WJ%n;
} ,mm9X\ '
Ps=<@,dks
0{Bhr12V
public void run() 6eq`/~#
{ Y V#|qb
while(nStartPos < nEndPos && !bStop) =Xu(Js-
{ eczS(KoL4
h$#zuqm
;{S7bH'6m
try{ m[E#$JZtG
URL url = new URL(sURL); y_A7CG"^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?CHFy2%Y
httpConnection.setRequestProperty("User-Agent","NetFox"); Zrm!,qs
String sProperty = "bytes="+nStartPos+"-"; rwCjNky!
httpConnection.setRequestProperty("RANGE",sProperty); kO'_g1f<[
Utility.log(sProperty); ^E|{i]j#f
ly)L%hG
\h UE,^
InputStream input = httpConnection.getInputStream(); ; w+<yW}EL
//logResponseHead(httpConnection); ^eHf'^Cvvu
<F#/wU^9
3X]\p}]z
byte[] b = new byte[1024]; d`ESe'j:
int nRead; 6j5?&)xJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g4=6\vg
{ &Rxy]kBA
nStartPos += fileAccessI.write(b,0,nRead); ptvM>zw'~g
//if(nThreadID == 1) RQt\_x7P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &.`/ln
} n=tg{_9f%
<'l;j"&lp
(14J~MDB
Utility.log("Thread " + nThreadID + " is over!"); B%^ $fJ|
bDownOver = true; N%" /mcO
//nPos = fileAccessI.write (b,0,nRead); Mg^.~8\de
} .BqSE
catch(Exception e){e.printStackTrace ();} &Dw8GU}1
} ?~fuMy B
} n3LCQ:]Tf
{nyVC%@Y
/m+q!yi &
//打印回应的头信息 eq(Xzh
public void logResponseHead(HttpURLConnection con) =h/0k y
{ u>I;Cir4
for(int i=1;;i++) @o6^"
{ `Q~`Eq?@
String header=con.getHeaderFieldKey(i); &f$[>yg1-
if(header!=null) ^d[s*,i?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); W$_@9W(Bl
Utility.log(header+" : "+con.getHeaderField(header)); wU=@,K
else i~04P
break; 6:o?@%
} jhmWwT/O8^
} %U$PcHOo
Vg^@6zU
]/C1pG*o
public void splitterStop() P0N%77p>"
{ SpG^kI #
bStop = true; g6=w MRt[
} #7~i.8L
Mb#-I GZ
#Kp/AN5YC
} =5yI>A0
V9o_Q
]\Tcy[5
/* V/jEMJNks
**FileAccess.java ?MhY;z`=
*//文件访问(定位，写) SKf[&eP,G
package NetFox; 8`/nk`;
import java.io.*; Y)=89s&t
(8*& 42W
2Hp#~cE+.
public class FileAccessI implements Serializable{ X)K3X:~L+
:"aCl~cy9g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tE: m& ;I
RandomAccessFile oSavedFile; %TA3o71
long nPos; fEl,jA
4Fr\=TX
fem>WPvG
public FileAccessI() throws IOException ~Z'3(n*9
{ K8l|qe
this("",0); D%0GXUp
} ttwfWfX
u!X$M?D4
4?AggqW
public FileAccessI(String sName,long nPos) throws IOException b]NSCu*)s
{ G^]7!:0
oSavedFile = new RandomAccessFile(sName,"rw"); jI8qiZ);~
this.nPos = nPos; yBPaGZ{f
oSavedFile.seek(nPos); `.FvuwP
} [V5ebj:6w
Bk~lE]Q3c7
,\|W,N}~
public synchronized int write(byte[] b,int nStart,int nLen) 9W{=6D86e
{ }lk_Oe1
int n = -1; 8W]6/st?]
try{ <Cvlz^K[
oSavedFile.write(b,nStart,nLen); H-9%/e
n = nLen; I]]3=?Y
} 1>"K<6b+
catch(IOException e) A&2)iQ
{ CE$c/d[N.
e.printStackTrace (); wPn#>\/L
} - T,;Fr'
/hef3DV5I
(=H%VXQH
return n; ?dukK3u
} TvE M{
S3[rv
+oZq~2?*S6
} K.Tfu"6
;J~NfL
1Z +3=$P
/* [=Y@Ul
**SiteInfoBean.java `5:Wv b>|
*/ cp0@wC#d
package NetFox; 8Vkw vc
gsn3]^X
2NLD7A
public class SiteInfoBean { SSKn7`
-,Q !:
W27EU/+3
private String sSiteURL; //Site's URL iw\RQ 0
private String sFilePath; //Saved File's Path G SXe=?
private String sFileName; //Saved File's Name :h tOz.
private int nSplitter; //Count of Splited Downloading File P"J(O<(1-:
a a=GW%
uoYG@L2
public SiteInfoBean() Cg/L/0Ak
{//nSplitter的缺省值为5 /2K4ka<?7
//default value of nSplitter is 5 !F*7Mif_E
this("","","",5); O+Fu zCWj
} gRS}Y8
i2SR.{&
,F7W_f# @3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bb#F2r4
{ hHsCr@i
sSiteURL= sURL; 0*MY4r|-
sFilePath = sPath; V]cD^Fqp
sFileName = sName; wuCiO;w
this.nSplitter = nSpiltter; <FIc!
ZR<T\w
$DZ\61
} 2r2qZ#I}
05mjV6j7m
%O`e!p
public String getSSiteURL() #Jv|zf5Z
{ 6fhH)]0
return sSiteURL; #5xK&qA
} Y '&&1R
~6z<tyD^
{OP[Rrm
public void setSSiteURL(String value) sas}k7m"
{ 7*8R:X+^r
sSiteURL = value; m$ZPQ0X
} @UCGsw
gwDQ@
TT3GFP
public String getSFilePath() \kU0D
{ 6]yYiz2Xn
return sFilePath; l2"{uCcA
} +jePp_3$O
v1Tla]d
)$XW~oA'
public void setSFilePath(String value) ^s/HbCA
{ !%{/eQFT4
sFilePath = value; B#Cb`b"
} o(GXv3L
p]/HZS.-b
m?DI]sIv#
public String getSFileName() f 4CS
{ 0b%"=J2/p.
return sFileName; {3F;:%$`c
} 45` i
~0"(C#l9
jj2 [Zh/h
public void setSFileName(String value) +;uP) "Q/L
{ e^)+bmh
sFileName = value; N t]YhO
} 8yEN)RqI
64Gd^.Z
qRkY-0vBP
public int getNSplitter() 'NyIy:
{ H`#{zt);
return nSplitter; p|!5G&O,
} U5N/'p%)<
e&WlJ
]v&)mK]n=o
public void setNSplitter(int nCount) h>AK^fX
{ fgrflW$
nSplitter = nCount; wVU.j$+_#
} xj8yQ Y1
} 0$)uOUVJ
HBHDu;u
\$GM4:R D
/* mw2/jA7
**Utility.java 8aDhHXI
*/ s8L=:hiSf)
package NetFox; 32nB9[l
a*?bnw?
nBw4YDR!
public class Utility { {~J'J$hn8
coa+@g,w7#
t5: 1' N9P
public Utility() L?_'OwaY
{ z,pKyInw
rCt8Q&mzf
En01LrC?
} {m%]`0
f793yCiG
//线程睡眠 zh8\ _>+
public static void sleep(int nSecond) +9LIpU&5
{ HK_Vk\e
try{ ^n Gj 7b
Thread.sleep(nSecond); Hw"LoVh
} r<< ]41
catch(Exception e) UnTnc6Bo7W
{ @">^2
e.printStackTrace (); ?'>pfU
} 'cp1I&>
} CK[w0VCT
,#n$YT7
//日志 N@}5Fnk-
public static void log(String sMsg) @8\7H'K"\
{ MTI[Mez
System.err.println(sMsg); 'M20v-[
} {`RCh]W
py\KY R
]#$l"ss,
public static void log(int sMsg) bhk:Szqz
{ d\eTyN'rA
System.err.println(sMsg); CuT~ Bj
} ~9Xs=S!
} +95: O 8
V46=48K.
=:neGqd\_E
/* >)`yG'[
**TestMethod.java #bIUO2yVo
*/ %?2:1o
package NetFox; Q[rmsk2L'
PMOyZ3
V LXU
public class TestMethod { K/T4T\
dZ6\2ok+
AFMIp^F
public TestMethod() dd?ZQ:n
{ ///xx/weblogic60b2_win.exe @wVq%GG}
try{ P5?M"j0/^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B}?$kp
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); e-&0f);i
SiteFileFetch fileFetch = new SiteFileFetch(bean); |.]g&m)y^h
fileFetch.start(); &];:uYmMU
} T)CEcz
catch(Exception e){e.printStackTrace ();} 5~ip N/)E
}Bk>'
Nbyc,a[o
} xZ=6
0,{tBo
"pA24Ze
public static void main(String[] args) yb/v?q?Fk
{ TyGsSc
new TestMethod(); %f-Uwq&}Y"
} {zNFp#z
} mMt~4(5
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