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)); t= =+SHGP
} E0 ~\ A;
for(int i=0;i<nEndPos.length-1;i++) ~4e4Gyx c
{ Uy$1X
nEndPos = nStartPos[i+1]; y7a84)j3
} >)E{Hs
nEndPos[nEndPos.length-1] = nFileLength; ''Lf6S`4X~
} ?)x"+[2
} K"lZwU\:On
QtM9G@%
9|y?jb5im
//启动子线程 OsQB` D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g<ZB9;FX %
for(int i=0;i<nStartPos.length;i++) rUJIf;Zwo
{ <#c/uIN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kkvG=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -u!{8S~wA
nStartPos,nEndPos,i); QfHJZ7K.4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :PJ5~7C
fileSplitterFetch.start(); ElBpF8xJ|o
} /*v}.fH%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &x= PAu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t@hE}R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VV'K$v3'N8
nEndPos = " + nFileLength); 9Tju+KcK
// fileSplitterFetch[nPos.length-1].start(); >m66j2(H*Z
WoYXXYP/E
x^0MEsR
//等待子线程结束 h5+L/8+J^z
//int count = 0; 5 5$J%;&
//是否结束while循环 ^)\z
boolean breakWhile = false; Zt3Y<3o
c-?2>%;(V
eaNMcC1
while(!bStop) 1$A7BP
{ tN-U,6c]
write_nPos(); NG)Xk[q4
Utility.sleep(500); T~&9/%$F
breakWhile = true; M.*3qWM
Q^p>hda
fWutB5?P
for(int i=0;i<nStartPos.length;i++) 5(+9( \x
{ oM<Y o%n
if(!fileSplitterFetch.bDownOver) R:[IH2F s
{ .|Ee,Un
breakWhile = false; 5:"zs
break; q!r4"#Y"@Z
} G; onJ>
} VZo,AP~
if(breakWhile) 948lL&
break; cq?&edjP
dc]D 8KX
ZJZKCdT@
//count++; 7QnQ=gu
//if(count>4) !%8|R]d
// siteStop(); ?H30
} ,.Sd)JB'
s]lIDp}
krt8yAkG
System.err.println("文件下载结束！"); 1G6 %?Iph
} B#Q=Fo 6
catch(Exception e){e.printStackTrace ();} @0v%5@
} ";>>{lYA.
Iz^lED
E <O:
//获得文件长度 $VgazUH% =
public long getFileSize() #0F6{&; M
{ s\Zp/-Q
int nFileLength = -1; M~o\K'
try{ +CQ$-3
URL url = new URL(siteInfoBean.getSSiteURL()); |o5F%1o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zA<Hj;9SM
httpConnection.setRequestProperty("User-Agent","NetFox"); ?J1x'/G
m0$4
eG F{.]
int responseCode=httpConnection.getResponseCode(); r6u) 6J=
if(responseCode>=400) #("/ 1N6
{ Z'@a@Y+
processErrorCode(responseCode); Y)7LkZO(y
return -2; //-2 represent access is error ^o|Gx
} 1vmK d
FlqE!6[[
l+V#`S*q
String sHeader; CSBk
4/Wqeq,E8
N8-!}\,
for(int i=1;;i++) k`u:Cz#aB
{ 'x{E#4A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =ghN)[AZV
//Utility.log(in.readLine()); m:sT)
sHeader=httpConnection.getHeaderFieldKey(i); x9lG$0k:V
if(sHeader!=null) \{Yi7V Xv
{ <-3_tu>l
if(sHeader.equals("Content-Length")) 8}A+{xVp8
{ U>@st="
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); HK/T`p#
break; u\uYq
} u*:;O\6l
} 13lJq:bM
else BPH-g\q
break; <,Z6=M`
} cc %m0p
} ?[`*z?}
catch(IOException e){e.printStackTrace ();} QsN%a>t
catch(Exception e){e.printStackTrace ();} $vQ#ah/k
}5I+VY7a
EU0b>2n4
Utility.log(nFileLength); 7E}.P1
>w}5\4j
#*"5F*
return nFileLength; Z}E.s@w
} GCEcg&s=\S
W ^MF3
ZtFOIb*
//保存下载信息（文件指针位置） ,{tK{XpS
private void write_nPos() |hlc#t?
{ kg@Okz N%
try{ R54wNm@
output = new DataOutputStream(new FileOutputStream(tmpFile)); GIyb0XjTw
output.writeInt(nStartPos.length); T/b%,!N)
for(int i=0;i<nStartPos.length;i++) O6gl[aZN
{ [;E~A
// output.writeLong(nPos); h>A~..
output.writeLong(fileSplitterFetch.nStartPos); Xc!0'P0T
output.writeLong(fileSplitterFetch.nEndPos); qMj'%5/
} lebwGW,!
output.close(); !qF U
} X5V8w4NN
catch(IOException e){e.printStackTrace ();} "%~Jb dx
catch(Exception e){e.printStackTrace ();} 5ml#/kE
} (H/2{##
Qel2OI`b
U<aT%^_
//读取保存的下载信息（文件指针位置） n&4 4Acs[
private void read_nPos() 3b#eB
{ `ecIy_O3P&
try{ DF>LN%a~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bJ$6[H-:
int nCount = input.readInt(); XlPi)3m4/S
nStartPos = new long[nCount]; wTu_Am
nEndPos = new long[nCount]; sFvu@Wm'7W
for(int i=0;i<nStartPos.length;i++) ]rpU3 3
{ 6BnP"R.
nStartPos = input.readLong(); ? _>L<Y
nEndPos = input.readLong(); .o._`"V
} .d4L@{V
input.close(); ^E)*i#."4
} nNN~Z'bG
catch(IOException e){e.printStackTrace ();} jIzkI)WC|
catch(Exception e){e.printStackTrace ();} `~0^fSww
} u@"nVHgMJ
D<DSK~
h.~:UR*
private void processErrorCode(int nErrorCode) 3 W%Bsqn
{ n[mVwQ(%
System.err.println("Error Code : " + nErrorCode); 5}pn5iI
} KliMw*5(
!ULU#2'1
nz?jNdyz
//停止文件下载 hhqSfafUX
public void siteStop() G[pDKELL
{ =}$YZuzmU
bStop = true; r}9a31i
for(int i=0;i<nStartPos.length;i++) &$,%6X"
fileSplitterFetch.splitterStop(); ;?*`WB
4dB6cg
g?}$"=B
} {D6E@a
} m$bX;F}T
//负责部分文件的抓取 v4pFts$J
**FileSplitterFetch.java 4GiHp7Y&A
*/ U:a-Wi+
package NetFox; YV6@SXy
|9Gng`)
_4#8o\
import java.io.*; 7eM:YqT/#
import java.net.*; *b$8O
sW53g$`v
Y/3CB
public class FileSplitterFetch extends Thread { tiTJ.uz6
`YK2hr
FE0}V}\=h
String sURL; //File URL |>Q]q
long nStartPos; //File Snippet Start Position <;O-N=
long nEndPos; //File Snippet End Position #dvH0LX?
int nThreadID; //Thread's ID DaA9fJ7a
boolean bDownOver = false; //Downing is over ')bas#=uP
boolean bStop = false; //Stop identical ^-*q
FileAccessI fileAccessI = null; //File Access interface (O$PJLI
gJ; *?Uq(
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pd3=^Zi
{ Y]u6f c
this.sURL = sURL; !mM`+XH
this.nStartPos = nStart; \z~wm&
this.nEndPos = nEnd; 0ESxsba
nThreadID = id; ];3]/b)&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 up# R9 d|
} d(=*@epjR
d4 Hpe>
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public void run() r I-A)b4
{ D?)^{)49
while(nStartPos < nEndPos && !bStop) )\k({S
{ y1oQ4|KSI
l/wdu(
"vH>xBR[%
try{ H*gX90{!2
URL url = new URL(sURL); 6t,_Xqg*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ib~n}SA
httpConnection.setRequestProperty("User-Agent","NetFox"); rt_k }
String sProperty = "bytes="+nStartPos+"-"; {\SJr:
httpConnection.setRequestProperty("RANGE",sProperty); d,hKy2
Utility.log(sProperty); )P>}uK;
prdlV)LTpY
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InputStream input = httpConnection.getInputStream(); bm</qF'T6
//logResponseHead(httpConnection); 7,.3'cCL^
}.L\O]~{
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byte[] b = new byte[1024]; .# Jusd
int nRead; JKXb$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l2&s4ERqSm
{ 6JCq?:#ab
nStartPos += fileAccessI.write(b,0,nRead); (>LJv |wn
//if(nThreadID == 1) "8NhrUX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wT taj08D
} 0bcbH9) 1q
@_ZE_n
n/&}|998?
Utility.log("Thread " + nThreadID + " is over!"); .8v[ss6:
bDownOver = true; qubyZ8hx
//nPos = fileAccessI.write (b,0,nRead); zFFip/z\
} q[wVC h
catch(Exception e){e.printStackTrace ();} ) ]y^RrD
} Yp;6.\Z8[
} G2,9$8qE
GY3g`M
Jn+k$'6%#
//打印回应的头信息 T1([P!g*
public void logResponseHead(HttpURLConnection con) RyN}Gz/YN
{ d,"6s=4(q
for(int i=1;;i++) `1hM3N.nO
{ gQ0W>\xz
String header=con.getHeaderFieldKey(i); b.4H4LV
if(header!=null) CZ~%qPwDw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "+REv_:
Utility.log(header+" : "+con.getHeaderField(header)); Jlw oSe:S
else lD!o4ZAo
break; )$/Gh&1G
} T/ CI?sn
} A#W%ud4
^;3z9}9
)*@Oz
public void splitterStop() ?-,v0#
{ krTH<- P
bStop = true; p~h=]o'i
} ]@op
h:[PO6GdX
A2z%zMlZc
} ?aInn:FE
Urhh)i
G3P3
/* :K&
**FileAccess.java S]Gw}d]4
*//文件访问(定位，写) fbSl$jn.
package NetFox; byM/LE7)
import java.io.*; Tx35~Z`0
.J3lo:
x%ZjGDFm
public class FileAccessI implements Serializable{ GEq?^z~i
b0]y$*{j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :8U=L'4
RandomAccessFile oSavedFile; x~xaE*r
long nPos; + )?1F
3e"_R
oUEpzv,J
public FileAccessI() throws IOException "])X0z yM
{ xaWd\]UF
this("",0); z2og&|uT
} L<Q1acoZm
#rzq9}9tB
Q"CZ}B1<
public FileAccessI(String sName,long nPos) throws IOException _s!(9
{ Zi/l.=9n
oSavedFile = new RandomAccessFile(sName,"rw"); Yt2_*K@rC
this.nPos = nPos; I ms?^`N
oSavedFile.seek(nPos); 3a9Oj'd1M
} ~=P&wBnJ
{mF:m5e
"8VCXD
public synchronized int write(byte[] b,int nStart,int nLen) Y_S^B)y
{ [V()7
int n = -1; ?s(%3_h
try{ wQ[~7 ,o
oSavedFile.write(b,nStart,nLen); y[S5
n = nLen; {Q^P<
} NFPW#-TF
catch(IOException e) AV AF!Z
{ -O3^q.
e.printStackTrace (); ,JRYG<O_T
} ?)-*&1cv
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x;lIw)Ti
return n; (L8H.|.
} rE[*iq,#
' A= x
+"Ek? )?
} "m):"
ow]S 3[07
Fkj\U^G
/* x$I~y D
**SiteInfoBean.java cC1nC76[
*/ pq+Gsu1^
package NetFox; e2UbeP
,\4@Ao
Z<K[
public class SiteInfoBean { I5>HB;Q
Q<P],}?:
4vPQuk!
private String sSiteURL; //Site's URL TLl*gED
private String sFilePath; //Saved File's Path Yn[y9;I{
private String sFileName; //Saved File's Name . [+ObF9=
private int nSplitter; //Count of Splited Downloading File gCz^JM
d"uR1rTk
v-Ggf0RF
public SiteInfoBean() x "]%q^x
{//nSplitter的缺省值为5 8},!t\j#]
//default value of nSplitter is 5 ["Ep.7=SU
this("","","",5); 'y}l9alF
} V/$qD
Duj9PV`2
E {4/$}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G9:[W"P
{ ;" '`P[
sSiteURL= sURL; lLxKC7b
sFilePath = sPath; Xl;u
sFileName = sName; HviL4iO
this.nSplitter = nSpiltter; &9, 6<bToP
b)(#/}jMkD
!FZb3U@
} \A*#a9"
>e($T!}Z
'{QbjG%<P
public String getSSiteURL() }N:0%Gk[;
{ |L.QIr,jCC
return sSiteURL; 66fvS}x
} 2TmQaDu%b
])'22sY
L9Z:>i?
public void setSSiteURL(String value) 0diQfu)Fi
{ PZKKbg2S
sSiteURL = value; #n]js7
} Q*ZqY
(ST/>")L
M,8a$Mdqh
public String getSFilePath() lV]hjt-L 2
{ \'&:6\-fw
return sFilePath; :-xp'_\L
} Ms=x~o'
&Zs h-|N
F/tBr%RV
public void setSFilePath(String value) u^s{r`/
{ ={~`0,
sFilePath = value; <oS2a/Nd
} ~=aGv%vX
eA$9)K1GO
Mou>|U1e"
public String getSFileName() Xnt`7L<L
{ L}P<iB
return sFileName; )Uw QsP
} k]u0US9/
gs_"H
wz+
public void setSFileName(String value) T|GRkxd,E3
{ {oy(08`6
sFileName = value; 'vgw>\X(
} :iD([V
cR 4xy26s
mhH[jO)
public int getNSplitter() F[ N{7C3
{ 30-XFl
return nSplitter; HTao)`.
} Us+|L|/
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KV k 36;$
public void setNSplitter(int nCount) 5u'"m<4
{ y&-wb'==p
nSplitter = nCount; *LOpbf
} vRp =L54z
} ;hA>?o_i(
s4Lqam!
)?^0<l#s
/* 1"RO)&
**Utility.java \|BtgT*$b
*/ dms R>Q
package NetFox; Aa[p7{e
MLtfi{;LH
hC4##pAa
public class Utility { Q9tBHz
a)^f`s^aa
Pni
public Utility() x[U/ 8#f&
{ F<Js"z+
y2gI]A
biKom|<nm
} JaoRkl?F
Bwj^9J/ob
//线程睡眠 5, R\tJCK
public static void sleep(int nSecond) cq>{
{ `of 5h*k
try{ !(~eeE}|lM
Thread.sleep(nSecond); 7tP?([o%F
} -D?T0>
catch(Exception e) vQ>x5\r5O_
{ ;)s$Et%
e.printStackTrace (); I:CnOpR>A
} N3 .!E|
} Tjma'3H*T0
e` Z;}& ,
//日志 x9k(mn%,
public static void log(String sMsg) J@PwN^`
{ _U(b
System.err.println(sMsg); ;wwhW|A
} bO]^TRaiJ
jq:FDyOAW
nd*9vxM
public static void log(int sMsg) f2ygN6(>
{ NBEcx>pma
System.err.println(sMsg); 8z0j}xY%
} 0h/gqlTK1
} GjN/8>/
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Fka&\9i
/* H^z6.!$m
**TestMethod.java rOQ@(aUAZ
*/ <9z2:^
package NetFox; 9Jd{HI=
qp3J/(F
^kJ(bBY
public class TestMethod { c<-F_+[
rDFDrviW_
kDI(Y=Fg
public TestMethod() {:BAh5e|
{ ///xx/weblogic60b2_win.exe Lf0Y|^!S_u
try{ ]D_"tQ?i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f'&30lF
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); GcN[bH(@
SiteFileFetch fileFetch = new SiteFileFetch(bean); ZGO%lkZ.
fileFetch.start(); Lc4\i
} VqGmZ|+8
catch(Exception e){e.printStackTrace ();} 8CCd6)cG
C".nB12
\GhL{Awv&a
} SNqw2f5
vF yl,S5A
XTboFrf
public static void main(String[] args) =nPIGI72VO
{ Wmri%
new TestMethod(); \yt-_W=[
} )H=}bqn
} );EW(7KeL
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