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)); >_]j{}~\k
} |}\et ecB
for(int i=0;i<nEndPos.length-1;i++) ,!3G
{ >T4.mB7+>
nEndPos = nStartPos[i+1]; P/?`
} "el}@
nEndPos[nEndPos.length-1] = nFileLength; Q': }'CI
} Xb=9~7&,$
} R1FBH:Iu
_{6QvD3kg.
Cv|ya$}a
//启动子线程 cSBYC_LU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nmVL%66K
for(int i=0;i<nStartPos.length;i++) W@1Nit-R
{ _d&FB~=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5TVDt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C-$S]6
nStartPos,nEndPos,i); hof:+aW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ajW[}/)
fileSplitterFetch.start(); _.OajE\T
} c?CjJ}-7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9Ay*'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5~CHj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0I4RZ.2*Y
nEndPos = " + nFileLength); a="Z]JGk
// fileSplitterFetch[nPos.length-1].start(); V7!x-E/
C9U~lcIS
o@r+Y
//等待子线程结束 eqQAst#~
//int count = 0; m#mM2Guxe
//是否结束while循环 g&H6~ +\
boolean breakWhile = false; `6b!W0$ -
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G_g~-[O
while(!bStop) i!<,8e=
{ auqM>yx
write_nPos(); HKCMKHR
Utility.sleep(500); =)(o(bfSKr
breakWhile = true; i3*S`/]p
";cWK29\f
YsXP$y]g-
for(int i=0;i<nStartPos.length;i++) z{cIG8z
{ ]n0kO&
if(!fileSplitterFetch.bDownOver) GmB7@-[QA%
{ b,8W |
breakWhile = false; a1Qg&s<
break; Tz1St{s\
} ^S'}RZ*>
} ;GO>#yg4Eh
if(breakWhile) ,YJ\ $?
break; Q_xE:#!;
yw2^kk93|
C+$dm)M/q
//count++; iK1<4)
//if(count>4) >n)N=Zyu
// siteStop(); V4}9f5FR
} HjV3PFg
-4o6OkK<
L{;q^
System.err.println("文件下载结束！"); qCn(~:
} <XX\4[wb
catch(Exception e){e.printStackTrace ();} Sb+pB58&N
} l)fF)\|;=
Qi#%&Jz>f
Z16G
//获得文件长度 R 28v5
public long getFileSize() s!``OyI/Z
{ ZJ@M}-4O1
int nFileLength = -1; #[C|%uq
try{ J (Yfup
URL url = new URL(siteInfoBean.getSSiteURL()); 0ejx;Mum
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iV[g.sP-
httpConnection.setRequestProperty("User-Agent","NetFox"); s(J,TS#I]
!9DqW&8
' D+h_*H
int responseCode=httpConnection.getResponseCode(); ~S15tZ $
if(responseCode>=400) .HF+JHIUu
{ %p)6m2Sb
processErrorCode(responseCode); |j$&W;yC
return -2; //-2 represent access is error @;M( oFS9
} 3Ln~"HwP
g= k}6"F~
i2/:' i
String sHeader; .{LFc|Z[
yv^j~
@dV'v{:,
for(int i=1;;i++) G eN('0
{ qi_[@da f?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wP- pFc
//Utility.log(in.readLine()); f@T/^|`mh
sHeader=httpConnection.getHeaderFieldKey(i); ~cVFCM
if(sHeader!=null) deHhl(U;
{ 1+v&SU
if(sHeader.equals("Content-Length")) C2Fklp6
{ Z!60n{T79c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V|ax(tHv
break; 2cr~/,YY
} 8Br*
} ;?1H&
else 2Otd
break; W)ihk\E
} I.A7H'j
} "]Wrir?l
catch(IOException e){e.printStackTrace ();} +^YXqOXU
catch(Exception e){e.printStackTrace ();} E!&A[TlX\
-bu.Ar-#;h
bv$_t)Xh
Utility.log(nFileLength); @T
:2{6Pa(eg
kG/:fP
return nFileLength; ifl`QZp_
} \dTX%<5D
lcHwKd
rlmzbIuI9
//保存下载信息（文件指针位置） +',[q
private void write_nPos() E8zga)
{ /UTeaM!?"
try{ N}b/;Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); kB{
output.writeInt(nStartPos.length); o8.KakrPP
for(int i=0;i<nStartPos.length;i++) 0m$f9b|Q?
{ ^AdHP!I
// output.writeLong(nPos); ?*|AcMw5
output.writeLong(fileSplitterFetch.nStartPos); im|( 4f
output.writeLong(fileSplitterFetch.nEndPos); trcG^uV
} Q{T6t;eH
output.close(); 7T9m@
} >Lx,<sE
catch(IOException e){e.printStackTrace ();} q 9lz
catch(Exception e){e.printStackTrace ();} ]l7) F-v
} kg?[
=<R")D]4z
'd4I/
//读取保存的下载信息（文件指针位置） S.1\e"MfI
private void read_nPos() [Hw
{ rXc-V},az8
try{ L|.q19b*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5wYYYo=
int nCount = input.readInt(); =/Pmi_
nStartPos = new long[nCount]; \B) a57
nEndPos = new long[nCount]; a|rN %hA4
for(int i=0;i<nStartPos.length;i++) ~=91Kxf
{ 5[}3j1
nStartPos = input.readLong(); Osncl5PD)
nEndPos = input.readLong(); 9W88_rE'e}
} ".A+'pJ
input.close(); NC'+-P'y
} 'NHtCs=F
catch(IOException e){e.printStackTrace ();} 1$T;u~vg
catch(Exception e){e.printStackTrace ();} "S)2<tV
} <qjNX-|
@q:v?AO
/8(c^
private void processErrorCode(int nErrorCode) ~XGBE
{ $Wt0e 4YSu
System.err.println("Error Code : " + nErrorCode); /(Mi2$@v1
} f.8Jp<S2K
mW~t/$Y$
|^9+c2
//停止文件下载 5Z"IM8?
public void siteStop() uvR9BL2=
{ JLo'=(
bStop = true; s+IU%y/9$a
for(int i=0;i<nStartPos.length;i++) vFKX@wV S
fileSplitterFetch.splitterStop(); gv)F`uRWA
4Gz5Ju
&AM<H}>
} 7R9.g6j
} vU,AOK[l{
//负责部分文件的抓取 kHLpa/A
**FileSplitterFetch.java vM )2F
*/ p|fSPSz
package NetFox; !lxs1!:
QcQQQM
C><]o
import java.io.*; .,Qj3
import java.net.*; eS)2#=
uG<VQ2LM
/]7FX"
public class FileSplitterFetch extends Thread { CR8a)X4j#
{6H%4n
GP=i6I6C
String sURL; //File URL |m{Q_zAB
long nStartPos; //File Snippet Start Position +/ s2;G
long nEndPos; //File Snippet End Position qYpuo D
int nThreadID; //Thread's ID [MLJs-*
boolean bDownOver = false; //Downing is over >d#oJ?goX
boolean bStop = false; //Stop identical h1O^~"x
FileAccessI fileAccessI = null; //File Access interface Z{-x}${
V)x(\ls]SX
qkQ_#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E.~;
{ !;Hi9,<#7g
this.sURL = sURL; DXX(qk)6
this.nStartPos = nStart; UrAg*v!Qy
this.nEndPos = nEnd; V.<$c1#=$
nThreadID = id; >JdA,i}1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X^204K%:
} C-25\
"mT95x\NA\
"s[Y$!#
public void run() ;/tZsE{
{ ^Ej4^d
while(nStartPos < nEndPos && !bStop) ?naPti1GX
{ p#-ov-znp
lIR0jgP@z
Hgu:*iYA
try{ nT7{`aaQl
URL url = new URL(sURL); [HEqMBX=;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n0nf;E
httpConnection.setRequestProperty("User-Agent","NetFox"); e| AA7
String sProperty = "bytes="+nStartPos+"-"; 4a'O#;ho
httpConnection.setRequestProperty("RANGE",sProperty); DGfhS`X
Utility.log(sProperty); ?Q$LIoR
/48W]a}JS
2 uuI_9 "^
InputStream input = httpConnection.getInputStream(); >y P`8Oq[
//logResponseHead(httpConnection); 2kv%k3Q{
D+$k
kk`BwRh)d;
byte[] b = new byte[1024]; -KzU''
int nRead; /cmnX'z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G`!ff
{ _W@SCV)yH
nStartPos += fileAccessI.write(b,0,nRead); dU!`aPL?
//if(nThreadID == 1) 3,`.$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NF?FEUoxz
} iQ[0d.(A
sU7>q}!
>;E[XG^
Utility.log("Thread " + nThreadID + " is over!"); qg7] YT&
bDownOver = true; sOyWsXd+R'
//nPos = fileAccessI.write (b,0,nRead); iz|mJUx
} w1zI"G~4/Q
catch(Exception e){e.printStackTrace ();} |.bp
} TmN}TMhZ
} IKJ~sw~AQ
O5"o/Y~m
eiLtZQ
//打印回应的头信息 WA);Z=
public void logResponseHead(HttpURLConnection con) P1PP#>E-2
{ &&1q@m,cP
for(int i=1;;i++) Sr7+DCr
{ E\M{/.4 4
String header=con.getHeaderFieldKey(i); DNgQ.lV
if(header!=null) wp/u*g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4fDo}~
Utility.log(header+" : "+con.getHeaderField(header)); 'pE %'8R
else |pIA9/~Z
break; L_+0[A
} Dl862$_Q
} nMU#g])y)
WY@x2bBi
f;/t7=>d
public void splitterStop() * *?mZtF
{ (wJtEoB9^
bStop = true; cz_4cMgxu
} lYd#pNN
V/5hEoDt
h6*=Fn7C
} T[$Sbz`
Z$R2Z$f
{HqwpB\@
/* Df_W>QC
**FileAccess.java &`7~vA&c
*//文件访问(定位，写) (vIrXF5Dnj
package NetFox; I3Sl>e(Z
import java.io.*; 1fbd/-h
0/.#V*KM
ArkFC
public class FileAccessI implements Serializable{ ixJUqo
-_jV.`t
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 inBd.%Yr
RandomAccessFile oSavedFile; H*QN/{|RU
long nPos; mRCgKW<
R|Ft@]
=#XsY,r
public FileAccessI() throws IOException A!v-[AI[
{ CiP-Zh[gZ
this("",0); @S~'m;
} }iy`Ko+B"b
$ql-"BB
_ED1".&#f
public FileAccessI(String sName,long nPos) throws IOException (.,E6H|zI
{ GS{:7%=j
oSavedFile = new RandomAccessFile(sName,"rw"); 6RZ[X[R[}
this.nPos = nPos; v)JQb-<
oSavedFile.seek(nPos); D} 0>x~
} :C42yQAP
&QOob)
FH8?W| G
public synchronized int write(byte[] b,int nStart,int nLen) }\u~He%
{ TJY$<:
int n = -1; 98C~%+
try{ [Hdk=p
oSavedFile.write(b,nStart,nLen); ,IUMH]D
n = nLen; NrvS/cI!t
} \3q{E",\>@
catch(IOException e) m@JU).NKCS
{ ;hs:wLVa"
e.printStackTrace (); 6\86E$f=h
} 2h&pm
;J\{r$q
BN4dr9T
return n; )<.S3
} wrG*1+r
#)R;6"
s)=L6t^a6
} lGB7(
#py7emu
>/n5=RWh
/* V`69%35*@
**SiteInfoBean.java se_zCS4Y
*/ ^F?H)[0
package NetFox; _0F6mg n
iy tSC
MbnV5b:X
public class SiteInfoBean { zi>f436-
~s^&*KaA
[ur/`
private String sSiteURL; //Site's URL mC~W/KReA
private String sFilePath; //Saved File's Path c%~'[W04\
private String sFileName; //Saved File's Name `@.YyPxX\
private int nSplitter; //Count of Splited Downloading File svpWABO
! # tRl
Lu:!vTRmw
public SiteInfoBean() q\#3G
{//nSplitter的缺省值为5 @7lZ{jV$
//default value of nSplitter is 5 jZv8X5i
this("","","",5); 8zj09T[
} l^`!:BOtR
Wr)%C
>mF`XbS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8KWTd
{ |[34<tIN
sSiteURL= sURL; C,PCU<q
sFilePath = sPath; Rl5}W\&
sFileName = sName; M/V >25`
this.nSplitter = nSpiltter; +G/~v`Bv
3"[ KXzn
M`?/QU~
} LR)is
\yG_wZs
f`Wfw3
public String getSSiteURL() tu!u9jVv
{ 56<LMY|d
return sSiteURL; kj0A%q#'}
} z5'VsK:
'&<-,1^L
He!0&B\7h
public void setSSiteURL(String value) Xkv>@7ec
{ #gN{8Yk>
sSiteURL = value; ]Vwky]d
} G|O"Kv6
W>@%d`>o5
L0&!Qct
public String getSFilePath() RM<\bZPc
{ M2xUs
return sFilePath; bkOm/8k|4
} j|aT`UH03
}4 $EN
-nk%He
public void setSFilePath(String value) G~esSL^G/
{ J"83S*2(j
sFilePath = value; 0_]aF8j
} +V'r>C:
},Z-w_H
BK /;HG
public String getSFileName() dfJ7Dhn
{ Ej34^*m9k
return sFileName; a|s=d
} [\.>BK
gdG: &{|x
ONfJ"Rp3
public void setSFileName(String value) +$ -#V
{ b&_p"8)_
sFileName = value; oNCDG|8z
} to?"{
hXrvb[6
pP/o2
public int getNSplitter() }bnkTC
{ Xr)d;@yi
return nSplitter; pH~JPNng
} gRqz8UI
ZRQPOy
!CMN/=
public void setNSplitter(int nCount) |y=gp
{ YJL=|v
nSplitter = nCount; X1'Ze,34
} ud#8`/!mq
} &1u?W%(Px
O0{v`|w9+
RCX4;,DHx
/* B+Bv(p
**Utility.java qnm9Lw#
*/ 3}gK`1Nq1
package NetFox; AN1bfF:C
z`2d(KE?
``z="oD
public class Utility { 0,3 ':Df
dk]ro~ [
7> ]C2!
public Utility() ~ dk1fh
{ Ce)Wvuh
UD(#u3z
`dNb%f>
} 7>mYD3
vSL{WT]m
//线程睡眠 h/VYH(Tj
public static void sleep(int nSecond) ]s SoIT
{ 2M1mdkP3
try{ ky%%H;
Thread.sleep(nSecond); Oxvw`a#
} A&7jE:Ew
catch(Exception e) `&6]P:_qp
{ :)yM9^<D
e.printStackTrace (); ^KF'/9S
} S\rfR N
} v;8XRR:
lpM{@JC
//日志 Smux&e
public static void log(String sMsg) fh3 6
{ $3Ia+O
System.err.println(sMsg); gc:>HX);)
} c8s/`esA
qs b4@jt+
>dGYZfqD
public static void log(int sMsg) 4>HGwk@+8
{ sP |i'
System.err.println(sMsg); CUG<v3\
} tSYnc7
} M:$nL
}.vy|^X
s#fmGe"8
/* <>oW f
**TestMethod.java iau&k`b`
*/ R}Y=!qjYE=
package NetFox; :F\f}G3
E;Hjw0M'k
<coCu0
public class TestMethod { Ye6O!,R
HXQrtJ
u5_fM*Ka
public TestMethod() 5b'S~Qj#r$
{ ///xx/weblogic60b2_win.exe qsRh ihPX
try{ Sx"I]N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d!:SoZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `y#C%9#
SiteFileFetch fileFetch = new SiteFileFetch(bean); \nWpV7TSN
fileFetch.start(); A&'%ou
} 8IH gsW";
catch(Exception e){e.printStackTrace ();} I2T2'_I
k#&SWp=
.#J3UZ
} co80M;4
YLo$n
M[{:o/]<
public static void main(String[] args) 1aG}-:$t'
{ ZM?r1Z4
new TestMethod(); ]l'ki8
} {@%(0d{n}
} >cb gL%
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