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)); $ {yct
} 4vhf!!1
for(int i=0;i<nEndPos.length-1;i++) MlO OB
{ -Cf)`/
nEndPos = nStartPos[i+1]; }$6L]
} oOFTQB_6
nEndPos[nEndPos.length-1] = nFileLength; nep#L>LP$x
} ttP7-y
} gt kV=V
^W |YE72Y
kUT2/3Vi
//启动子线程 X2w)J?pv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X+vKY
for(int i=0;i<nStartPos.length;i++) I8H3*DE
{ ^z,3#gK
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *_V+K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rYUIFPN
nStartPos,nEndPos,i); $H:!3-/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Szo'[/ [R
fileSplitterFetch.start(); xATx2*@X2
} ">V&{a-C4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~(kEGEF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); osV6=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GT{4L]C
nEndPos = " + nFileLength); 72HA.!ry
// fileSplitterFetch[nPos.length-1].start(); D%SOX N
XM'tIE+|
w[~G^x&
//等待子线程结束 m^X51,+<
//int count = 0; )g5?5f;
//是否结束while循环 ;0DoZ
boolean breakWhile = false; 9>RkFV
$b8[/],
An2>]\L
while(!bStop) Kda'N$|`
{ mc{z
write_nPos(); !Ko2yn}6l
Utility.sleep(500); 3(YvqPp&
breakWhile = true; qs4jUm
)f?I{
!gh8 Qs
for(int i=0;i<nStartPos.length;i++) r$jWjb
{ R%r bysP
if(!fileSplitterFetch.bDownOver) Tigw+2
{ 6St=r)_
breakWhile = false; |Xt G9A>
break; xAmtm"
} X[Y0r
} |}zWH=6
if(breakWhile) %m&6'Rpfk
break; f*k7 @[rSv
qxZIH
y)kxR
//count++; y-<.l=6A
//if(count>4) Nd8>p.iqO
// siteStop(); CKAd\L
} {}$9 70y
-CPtYG[s
7x)Pt@c
System.err.println("文件下载结束！"); jAJ='|[X\
} 3,PR6a,b'
catch(Exception e){e.printStackTrace ();} mK:gj&N7X|
} ^PG"
O9ex=m `L
|q`NJ
//获得文件长度 VL%. maj
public long getFileSize() WJ{Iv] }9
{ 7_~ A*LM
int nFileLength = -1; ~yv7[`+Tgg
try{ b]u$!W
URL url = new URL(siteInfoBean.getSSiteURL()); Xhe& "rM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Emlj,c<?j
httpConnection.setRequestProperty("User-Agent","NetFox"); *)m:u:
5c- P lm%
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int responseCode=httpConnection.getResponseCode(); rPH7 ]]
if(responseCode>=400) \Vc[/Qp7Bb
{ rr#nBhh8
processErrorCode(responseCode); 9r%fBiSk
return -2; //-2 represent access is error t]K20(FSN
} oR#W@OK@is
<rC%$tr
o.KnDY
String sHeader; ]4aPn
s`yzeo
% /:1eE`!S
for(int i=1;;i++) -K|1w'E
{ ly[yn{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IQ&PPC
//Utility.log(in.readLine()); WNR]GI
sHeader=httpConnection.getHeaderFieldKey(i); vF\>;pcT
if(sHeader!=null) gP_N|LuF"
{ : (UK'i
if(sHeader.equals("Content-Length")) uFr12ZFgK
{ 0/HFLz'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M9)4ihK
break; /@:X0}L
} >n7h%c
} 0CzQel)L:
else cSL6V2F
break; *\ii+f-
} I`_2Q:r
} (%_X{R'
catch(IOException e){e.printStackTrace ();} l";Yw]:^
catch(Exception e){e.printStackTrace ();} f' A$':Y
#j2kT
k>&cHCS`*
Utility.log(nFileLength); =.`\V]
7@@g|l]
RV~t%Sw^
return nFileLength; m6R/,
} =3-=p&*
3IYFvq~
kf@JEcKV
//保存下载信息（文件指针位置） 1PY]Q{r
private void write_nPos() )kep:-wm
{ ^ZMbJe%L
try{ rrL.Y&DTK
output = new DataOutputStream(new FileOutputStream(tmpFile)); [,Ehu<mEK
output.writeInt(nStartPos.length); L<FXtBJ
for(int i=0;i<nStartPos.length;i++) E{ /, b)
{ /LFuf`bXV
// output.writeLong(nPos); vyZ&%?{*R
output.writeLong(fileSplitterFetch.nStartPos); dN5{W0_
output.writeLong(fileSplitterFetch.nEndPos); 8N&'n
} oAO{4xP
output.close(); n/KO{:
} (d4btcg
catch(IOException e){e.printStackTrace ();} V]|X ,G
catch(Exception e){e.printStackTrace ();} y:)^*2GA-B
} *JK0X
]:e_Y,@
izP)t
//读取保存的下载信息（文件指针位置） C0N :z.)4
private void read_nPos() l"ms:v
{ B[8bkFS>]
try{ s{b\\$Rb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Jc":zR@5
int nCount = input.readInt(); O9daeIF0#
nStartPos = new long[nCount]; Pd7\Q]of
nEndPos = new long[nCount]; 8"%Es
for(int i=0;i<nStartPos.length;i++) Q6m8N
{ R-%6v2;ry
nStartPos = input.readLong(); $0$sM/%
nEndPos = input.readLong(); NP;W=A F
} 0AHQ(+Ap
input.close(); tV!?Ol
} ^PEw#.WG
catch(IOException e){e.printStackTrace ();} "Z&.m..gc
catch(Exception e){e.printStackTrace ();} v,i|:;G
} "t^v;?4
W>#yXg9
gqS9{K(f
private void processErrorCode(int nErrorCode) 0+SDFh
{ tWn dAM(U7
System.err.println("Error Code : " + nErrorCode); a&>NuMDI
} +q&Hj|;8r
SnE^\I^O
?^voA.Bv<
//停止文件下载 d,GOP_N8I
public void siteStop() |Gic79b
{ X['9;1Xr
bStop = true; 6f +aGz
for(int i=0;i<nStartPos.length;i++) f<8Hvumw
fileSplitterFetch.splitterStop(); lpG%rN!
^/BGOBK
k6CXuU
} ;VE y{%nF
} m*m),mZ"
//负责部分文件的抓取 >Y>R1b%
**FileSplitterFetch.java 811>dVq3/
*/ #gbB// <
package NetFox; 2.3_FXSt
[6a-d>e{
&_L%wV|[
import java.io.*; l~E~!MR
import java.net.*; Ef]Hpjvp
vH+g*A0S<
tA#Pc6zBuC
public class FileSplitterFetch extends Thread { :|;@FkQ
[v~,|N>w
coAXYn
String sURL; //File URL 5{'hsC
long nStartPos; //File Snippet Start Position lp}S'^ y
long nEndPos; //File Snippet End Position #,tT`{u1q
int nThreadID; //Thread's ID _v&fIo
boolean bDownOver = false; //Downing is over LO=U?`)q
boolean bStop = false; //Stop identical ZA="Dac
FileAccessI fileAccessI = null; //File Access interface 8e?/LA%MU
'dwW~4|B
6U{A6hH]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T#B#q1/
{ dJR[9T_OF
this.sURL = sURL; sqKx?r72
this.nStartPos = nStart; vIpL8B86a
this.nEndPos = nEnd; VKttJok1
nThreadID = id; m?(8T|i
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (H_dZL
} ;MN$.x+
T >8P1p@A,
iTHwH{!
public void run() x)C}
{ j*>J1M3E
while(nStartPos < nEndPos && !bStop) D1rVgM
{ u=0O3-\h
{JfQQP&FV
|<Ls;:5.
try{ \\SQACN
URL url = new URL(sURL); p{Q6g>?[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yV.p=8:
httpConnection.setRequestProperty("User-Agent","NetFox"); ]c>@RXY'
String sProperty = "bytes="+nStartPos+"-"; m[}P
httpConnection.setRequestProperty("RANGE",sProperty); v_XN).f;
Utility.log(sProperty); P}4&J ^
.HZd.*
h,{Q%sqO
InputStream input = httpConnection.getInputStream(); V&f*+!!2
//logResponseHead(httpConnection); _*~F1% d
# `=Zc7gf
`4*I1WZW
byte[] b = new byte[1024]; b~zSsws.
int nRead; 'OnfU{Ai
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5Od%Jhtt
{ PIH\*2\/
nStartPos += fileAccessI.write(b,0,nRead); 7.29'
//if(nThreadID == 1) 7wj2-BWa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4vg3F(
} :$D*ab^^P
ehW[LRtq
qcs) p
Utility.log("Thread " + nThreadID + " is over!"); 7 z
bDownOver = true; 8C{&i5kj\E
//nPos = fileAccessI.write (b,0,nRead); 5qrD~D'
} b^HDN(v
catch(Exception e){e.printStackTrace ();} 2}&ERW
} 6La[( )
} QVjHGY*R
^(JrOh'
`%Fp'`ZM$8
//打印回应的头信息 OG}890$n
public void logResponseHead(HttpURLConnection con) x;[ .ZzQ
{ n~629&
for(int i=1;;i++) d.+*o
{ 4.,EKw3
String header=con.getHeaderFieldKey(i); :-{"9cgFR
if(header!=null) CmB_g?K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %gmx47
Utility.log(header+" : "+con.getHeaderField(header)); Bj7*2}
else XH%pV
break; /[TOy2/;%b
} UIEvwQ
} s*GZOz
\kQ)fk]^
]~;*9`:
public void splitterStop() P|Aac,nE+^
{ _&, A
bStop = true; |!(8c>]Bo
} =G}a%)?As\
[bnu DS
\~#\ [r_
} [R4#bl
yepRJ%mp
NAo.79
/* *fm?"0M5
**FileAccess.java Fbo"Csn_
*//文件访问(定位，写) *z[vp2 TN
package NetFox; 9i\}^s2
import java.io.*; Tu(:?
z<eu=OD4t
+c_AAMe
public class FileAccessI implements Serializable{ <~mqb=qA$
@_`r*Tb)dM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "[ LUv5
RandomAccessFile oSavedFile; g/C 7wc
long nPos; |&@q$d
%uo8z~+
j#f/M3
public FileAccessI() throws IOException OmuE l>
{ :Pq&l.
this("",0); "1s ]74
} $2Wk#F2c=
=\]gL%N-|
w5z]=dN
public FileAccessI(String sName,long nPos) throws IOException `)a|Q
{ 7Q/H+)
oSavedFile = new RandomAccessFile(sName,"rw"); lB27Z}
this.nPos = nPos; p>)1Z<D"a
oSavedFile.seek(nPos); =+X*$'<J
} W,~*pyLdO
++~ G\T9H
1tXc7NA<
public synchronized int write(byte[] b,int nStart,int nLen) d*+}_EV)Y3
{ 8nI~iN?"
int n = -1; q5g_5^csM{
try{ VQ!4( <XD
oSavedFile.write(b,nStart,nLen); 9]3l'
n = nLen; r5&c!b\
} ScJ:F-@>
catch(IOException e) xd3mAf
{ cPIyD?c
e.printStackTrace (); L^e*_q2d:>
} 2>"{El|PbN
HV!P]82Pa
.:H'9QJg
return n; %;4#?.W8
} _3 [E$Lg
wSjy31
5S? "<+J'
} UP-2{zb |?
9>+>s ?IgK
nxN("$'cq
/* zpT{!V
**SiteInfoBean.java |g7)A?2J~
*/ NH/jkt&F[
package NetFox; mV]~}7*Y;
<;i&-,
Z2{$FN
public class SiteInfoBean { B#."cg4VR
C|}yE;*a
'q9Ejig
private String sSiteURL; //Site's URL ]Q^8 9?
private String sFilePath; //Saved File's Path ])pX)(a
private String sFileName; //Saved File's Name -6 v?iiZr
private int nSplitter; //Count of Splited Downloading File lU|ltnU
6Hc25NuQZ
7# 'j>]
public SiteInfoBean() Uj 3{c
{//nSplitter的缺省值为5 F4(;O7j9
//default value of nSplitter is 5 &[\zs&[@y
this("","","",5); &>B|?d
} !5+9~/;
*RkvM?o@jC
~=wBF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,hK =x
{ mp3Dc
sSiteURL= sURL; tc;$7F ;
sFilePath = sPath; j,,#B4b
sFileName = sName; WV}pE~
this.nSplitter = nSpiltter; JF&$'
k'$7RjCu
lItr*,A]
} =uwG.,lC
;F_&h#D]3
?{Xp'D\z
public String getSSiteURL() s5 Fn("h]n
{ yPbOiA*lHz
return sSiteURL; HH!SqkwT
} *=z.H *
|q o3 E
hQSJt[8My
public void setSSiteURL(String value) 5}NO~Xd<
{ 6O5E4=
sSiteURL = value; p*P0<01Z
} 7;}TNK\+v
ku^2K
C~iFFh6:
public String getSFilePath() kGq<Zmy|
{ VAxk?P0j6
return sFilePath; _}Gs9sHr0K
} RkdAzv!Y7
# 9f 4{=\
7Ph+Vs+h
public void setSFilePath(String value) `Geq,
{ d\z':d.Tt
sFilePath = value; 43J8PMY
} }=3W(1cu-
HSl$ U0
]*S_fme
public String getSFileName() ,/L_9wV-\
{ 1_W5@)
return sFileName; Qe/=(P<
} Hi{!<e2
Q!%CU8!`&
~?A,GalS
public void setSFileName(String value) "ZVBn!
{ }\ui}\
sFileName = value; 5Q72.4HH
} :kI x?cc
.uagD[${
d>4e9M"
public int getNSplitter() B<'V7#L_
{ H+2J.&Ch
return nSplitter; HNoh B4vt
} $j}sxxTT
e$(i!G)
7 -V_)FK2c
public void setNSplitter(int nCount) f4T-=` SO
{ ?Ve5}N
nSplitter = nCount; S+OI?QS
} ")M.p_b[Z=
} u= +
f{z%PI[
{78*SR
/* PuABS>.;
**Utility.java ~KfjT p#
*/ -+I! (?
package NetFox; <F.Ol/'h
7#|NQ=yd
Xhkw<XbV
public class Utility { &akMj@4;R
s9:2aLZ{
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public Utility() Q}Vho.N@=
{ |-aj$u%~
1aMBCh<}JN
|QgXSe7
} ;%z0iZmg
0Rk'sEX,
//线程睡眠 01q7n`o#zf
public static void sleep(int nSecond) @%cJjZ5y
{ s3kEux^
try{ gZ!(&u
Thread.sleep(nSecond); x!.VWGtb
} FZ2-e
catch(Exception e) hJ4.:
{ <,hBoHZSL
e.printStackTrace (); ze\~-0ks+
} /7"1\s0U
} |95/'a*
`oz7Q(`
//日志 =L wX+c
public static void log(String sMsg) Oc'z?6axWv
{ SCH![Amq
System.err.println(sMsg); o%9>elOju
} -MEz`7c~
Gf]s?J^a
Pd;ClMa%
public static void log(int sMsg) EIEq[`h
{ < 5_Ys
System.err.println(sMsg); 9FLn7Y
} Po4cbFZ
} |8`;55G
TgB;R5
PrKlwhi#
/* QF;<%QF:
**TestMethod.java NU(/Yit
*/ )Z%+~n3o'
package NetFox; ,]{NZ9
g^4FzJ
=U2Te
public class TestMethod { .}<B*e=y
9iy|=
@ :4Kk 4g1
public TestMethod() 3ElpS^2W
{ ///xx/weblogic60b2_win.exe l=]vC +mU
try{ XZ&v3ul
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hw'2q9J|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E$>e< T
SiteFileFetch fileFetch = new SiteFileFetch(bean); {G0)mp,
fileFetch.start(); Xbtv}g<0c
} (}}8DB
catch(Exception e){e.printStackTrace ();} RZtL<2.@
uY~A0I5Z
ck~xj0
} c-=0l)&'D=
^Q,/C8qeb
a*[\edcHU
public static void main(String[] args) ed*AU,^@v
{ X[~CLKH(
new TestMethod(); g[jZ A[[
} LI<5;oE;
} ;MJ1Q
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