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)); Wd 2sh
} XB\zkf_}Xc
for(int i=0;i<nEndPos.length-1;i++) 6Z! y
{ T[uDZYx
nEndPos = nStartPos[i+1]; k*$3i
} X[hM8G
nEndPos[nEndPos.length-1] = nFileLength; o'=VZT9
} Oh!(@
} PpOlt.yui
5M){!8"S)#
NoDZ5Z
//启动子线程 0!#;j{JQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E`D%PEps+
for(int i=0;i<nStartPos.length;i++) f`P9ku#j}
{ Qi=*1QAkr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i$Z#9M9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M?@pN<|
nStartPos,nEndPos,i); _m'ysCjA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fE;Q:# Z.
fileSplitterFetch.start(); 8A2z 5Aa
} ">90E^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1/iE`Si
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cf;Ht^M\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AtHS@p
nEndPos = " + nFileLength); uofLhy!
// fileSplitterFetch[nPos.length-1].start(); f(Hu {c5yV
j}WByaZ&
h4`9Cfrq,
//等待子线程结束 tYe:z:7l?<
//int count = 0; !]b@RUU
//是否结束while循环 'gTmH[be
boolean breakWhile = false; NPJ.+ph
(6qsKX
;e{5)@h$
while(!bStop) K{DAOQ.z
{ Y;Y1+jt
write_nPos(); TSto9$}*
Utility.sleep(500); K0fv( !r{
breakWhile = true; ;VzMU ;j
*xH\)|3,
8vD3=yK%^
for(int i=0;i<nStartPos.length;i++) |4>:M\h
{ n9oR)&:o
if(!fileSplitterFetch.bDownOver) b|?;h21rG
{ optBA3@e!
breakWhile = false; z+VV}:Q
break; s>[{}7ca
} p@I9<^"
} h)dRR_
if(breakWhile) /1.rz{wpb
break; U{#xW
iuAq.$oi{
\ P/W8{
//count++; ; B$*)X9
//if(count>4) L.)yXuo4
// siteStop(); >)c9|e=8
} d-$_|G+
>BoSw&T$Q
DeQDH5X"
System.err.println("文件下载结束！"); dgc&[
} T33|';k
catch(Exception e){e.printStackTrace ();} u''BP.Y S
} YoSQN/Z
@ss):FwA
+R\~3uj[7
//获得文件长度 |63Y >U"
public long getFileSize() Bc ^4 T1
{ jnBC;I[:
int nFileLength = -1; o)I/P<
try{ Fd8hGj1
URL url = new URL(siteInfoBean.getSSiteURL()); d*-Xuv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =AkX4k
httpConnection.setRequestProperty("User-Agent","NetFox"); x_:hii?6V
nVOqn\m-
v33T @
int responseCode=httpConnection.getResponseCode(); J(9=T<%T
if(responseCode>=400) o#{#r@,i
{ kL;t8{n
processErrorCode(responseCode); {ymb\$f
return -2; //-2 represent access is error r{ @ `o@q
} (%DRt4u<H
=K'L|QKF
O),I[kb
String sHeader; >q9{
0k1MKzi Q
MSYN1
for(int i=1;;i++) $u5.!{Wq?
{ ,nYZxYLf+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cU | _
//Utility.log(in.readLine()); !5.v'K'
sHeader=httpConnection.getHeaderFieldKey(i); ;=p;v .l
if(sHeader!=null) WZ*&@|w
{ Sx&mv.?X
if(sHeader.equals("Content-Length")) :ICr\FY$
{ sU%"azc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eH[y[~r
break; fsI`DjKi)
} #W5Yw>$
} /(zB0TEd
else D_ ug-<QT
break; 3"tg+DncC
} 3- )kwy6L
} 8IOj[&%0
catch(IOException e){e.printStackTrace ();} B;c=eMw
catch(Exception e){e.printStackTrace ();} *vs~SzF$
#pa\2d|
k2uBaj]
Utility.log(nFileLength); t>oM%/H
0UjyMEiK
9|a)sb7/
return nFileLength; $4h04_"
} ~UW{)]_jox
Q9q9<J7j$
M6x;BjrV
//保存下载信息（文件指针位置） Y[,U_GX/R
private void write_nPos() >fwlg-
{ Eq7gcDQ
try{ G>j"cj
output = new DataOutputStream(new FileOutputStream(tmpFile)); +V89J!7
output.writeInt(nStartPos.length); S41)l!+2
for(int i=0;i<nStartPos.length;i++) gTD%4V
{ STRyW Ml
// output.writeLong(nPos); ZjavD^ky
output.writeLong(fileSplitterFetch.nStartPos); HnK/A0jM
output.writeLong(fileSplitterFetch.nEndPos); dw99FA6
} 5j1 IH,yW
output.close(); p1?J
} a;yV#Y
catch(IOException e){e.printStackTrace ();} auoA
catch(Exception e){e.printStackTrace ();} L]NYYP-
} d-i&k(M
|{!Ns+'
oHRbAE^
//读取保存的下载信息（文件指针位置） qKx59
private void read_nPos() i*b4uHna
{ SmvwhX
try{ MHn&; A]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3]7ipwF2q
int nCount = input.readInt(); `7$Oh{67
nStartPos = new long[nCount]; ,gx$U@0Z
nEndPos = new long[nCount]; I')x]edU
for(int i=0;i<nStartPos.length;i++) ^CX,nj_(
{ /Sh4pu"'
nStartPos = input.readLong(); *fOIq88
nEndPos = input.readLong(); DW4MA<UQ
} ls]Elo8h1f
input.close(); WT1q15U(=
} =mAGD*NKu
catch(IOException e){e.printStackTrace ();} Z%A<#%
catch(Exception e){e.printStackTrace ();} @Zh8 QI+
} Y~x`6
Wd1 IX^7C%
tUn&z?7bF
private void processErrorCode(int nErrorCode) 5 u"nxT
{ v.]'%+::#
System.err.println("Error Code : " + nErrorCode); d`<#}-nh
} 2/UI>@By
P@-R5GK
Mof)2Hbd:
//停止文件下载 9EjjkJ%)q
public void siteStop() HMFl/%z
{ RNl\`>Cz
bStop = true; 5auL<Pq
for(int i=0;i<nStartPos.length;i++) }]Qmt5'NI
fileSplitterFetch.splitterStop(); >DkN+S
~c9vdK
#{?m
} R|6RI}
} i"ck`6v"8
//负责部分文件的抓取 C-_w]2MM
**FileSplitterFetch.java J>/Ci\OB
*/ OcLg3.:L
package NetFox; / *Ou$
lxr@[VQ
1\=pPys)
import java.io.*; R20a(4m
import java.net.*; 56VE[G
@m }rQT
5IwX\
public class FileSplitterFetch extends Thread { `*|LI
H@Kl
]5aux >.n
String sURL; //File URL Z&BM%.NZJ
long nStartPos; //File Snippet Start Position 44g`=o@
long nEndPos; //File Snippet End Position ^?81.b|qb
int nThreadID; //Thread's ID \E>%W
boolean bDownOver = false; //Downing is over tOu90gu
boolean bStop = false; //Stop identical vK[v eFH
FileAccessI fileAccessI = null; //File Access interface =kyJaT^5[
O[3q9*(
a-SB1-5jf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2M!+gk=+
{ I67k M{V
this.sURL = sURL; zDKLo 3:
this.nStartPos = nStart; 0W!VV=j<}
this.nEndPos = nEnd; IiYuUN1D
nThreadID = id; e_;%F`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '|h./.K
} #mi0x06
QYFN:XZ
7H/!rx
public void run() rHA/
{ v3iDh8.__
while(nStartPos < nEndPos && !bStop) (UbR%A|v;
{ ]QjXh>
./aZV
)&g2D@+{
try{ 9`hpa-m@
URL url = new URL(sURL); *q\HFI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #khyy-B=
httpConnection.setRequestProperty("User-Agent","NetFox"); >Rx8 0
String sProperty = "bytes="+nStartPos+"-"; 6i*p +S?U"
httpConnection.setRequestProperty("RANGE",sProperty); *m `KU+o-u
Utility.log(sProperty); btr x?k(
1o"y%*"
38zR\@'j]4
InputStream input = httpConnection.getInputStream(); :y<Cd[/
//logResponseHead(httpConnection); <S:,`v&Z
n0 fF,?gm
=6L:Ix
byte[] b = new byte[1024]; ^D>/wX\u
int nRead; {H~8'K-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FRs|!\S=
{ o3(|FN
nStartPos += fileAccessI.write(b,0,nRead); A3<P li
//if(nThreadID == 1) n57c^/A*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hzk1LKsT#
} Wb*T
U?+30{hb
'Sb6 w+
Utility.log("Thread " + nThreadID + " is over!"); 7.F& {:@_
bDownOver = true; W! 5Blo
//nPos = fileAccessI.write (b,0,nRead); )%nt61P\W
} &B{Jxc`VA
catch(Exception e){e.printStackTrace ();} c@"i?
} -jklH/gF\%
} z}Mb4{d1
V2<k0@y
E Ni%ge'":
//打印回应的头信息 ijR*5#5h
public void logResponseHead(HttpURLConnection con) &Pn%zfmMN
{ Bm2}\KOI
for(int i=1;;i++) cfO^CC
{ )f_"`FH0d
String header=con.getHeaderFieldKey(i); &].1[&M]
if(header!=null) "O"^\f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d-K5nRyI
Utility.log(header+" : "+con.getHeaderField(header)); hP6fTZ=Ln
else Yg:74; .
break; F#3$p$;B$
} r4z}yt+
} AS/\IHZ\
?8aWUgl
R'$ T6FB5
public void splitterStop() t'_,9
{ y:(C=*^<t
bStop = true; }lQn]q
} 3GuMiht5
Y/Gswcz
G~mB=]
} El8.D3
P^d.,
lk *QV
/* +{l3#Y
**FileAccess.java #,|_d>p:
*//文件访问(定位，写) C[/Uy
package NetFox; l1.Aw|'D
import java.io.*; 30T:* I|
E]e[Ty1
hH@o|!y
public class FileAccessI implements Serializable{ Y9c9/_CSj
IWbp^l+!t
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 k)4lX|}Vm
RandomAccessFile oSavedFile; |2c!t$O@v
long nPos; CI3_lWax%
%lq7; emtp
Fw8X$SE"
public FileAccessI() throws IOException tg%WVy2
{ 5eZg+ O
this("",0); ]Rys=.!
} dA!fv`,6-
',xsUgk
}od7YL
public FileAccessI(String sName,long nPos) throws IOException Z ysUz
{ ]ge^J3az$u
oSavedFile = new RandomAccessFile(sName,"rw"); :_[cT,3
this.nPos = nPos; '| Q*~Lh
oSavedFile.seek(nPos); AFF>r#e
} '\vmfp=
k-Hfip[ro
7^Q$pT>
public synchronized int write(byte[] b,int nStart,int nLen) R~mMGz
{ i?s&\3--Y
int n = -1; 07WIa@Q
try{ sNan"
oSavedFile.write(b,nStart,nLen); sN \}Q#:8
n = nLen; Ph!NYi,
} CIs1*:Q9
catch(IOException e) t2%bHIG}
{ Nv$gKC6 ,G
e.printStackTrace (); 0:(dl@I)@
} Vm%ux>}
kjYO0!C
!6i
return n; fw~%^*
} [T?6~^m=
:^.87>V7
j$i8@]
} HFCFEamBMP
=.2cZwxX$
{m*J95[
/* 'H-YFB$l
**SiteInfoBean.java t6>Qe
*/ SvpTs
package NetFox; F#C6.`B
Sy7^;/(ZZ
`0gK;D8t
public class SiteInfoBean { WOTu"Yj
a9q?9X
LCm}v&~%A
private String sSiteURL; //Site's URL b(rBha|
private String sFilePath; //Saved File's Path 3<Y;mA=hw
private String sFileName; //Saved File's Name sn-+F%[
private int nSplitter; //Count of Splited Downloading File :usBeho
IXk'?9
*/h9"B
public SiteInfoBean() (HD>vNha1
{//nSplitter的缺省值为5 K{|dt W&
//default value of nSplitter is 5 `Q_ R/9~
this("","","",5); HC, 0"W
} @^jLYu|W
4]Nr$FY
3ncvM>~g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vM;dPE7
{ 6L% R@r
sSiteURL= sURL; S{|)9EKw
sFilePath = sPath; -`1L[-<d=/
sFileName = sName; BGYm]b\j[
this.nSplitter = nSpiltter; G6ES]
p:n^c5
&ZFAUE,[
} <cc0phr
F[giq1#
D`@U[`Sw
public String getSSiteURL() i'LTKj
{ aV%rq9Tp
return sSiteURL; L6}x3
} "TNUw&ih
.T>}O0L"
*X55:yha
public void setSSiteURL(String value) D`ge3f8Wi
{ =ZL}Av}
sSiteURL = value; DG FvRB
} <^Nj~+G'
gQt@xNO
1VsEic
public String getSFilePath() HWAqJb [
{ e-av@a3
return sFilePath; s+~Slgl
} L2A#OZZu
b-/x
PP`n>v=n
public void setSFilePath(String value) j %0_!*#3
{ h\ek2K
sFilePath = value; ,H1~_|)<
} dNt|"9~&
S.4YC>E
oeKc-[r
public String getSFileName() D6:J*F&?
{ 2^lT!X@
return sFileName; ?pY!sG
} ==r|]~x
NX",e=
!\ukb
public void setSFileName(String value) 6-YR'ikU
{ Vb#@o)z
sFileName = value; R?Q-@N>wE
} AWNd(B2o
G{Q'N04RA
&fj?hYAj
public int getNSplitter() mR@Xt#
{ n?tAa|_
return nSplitter; Y%9F
} rq?x]`u
n(1"6
&4FdA|9T
public void setNSplitter(int nCount) &3?yg61Ag
{ sYgnH:t X
nSplitter = nCount; )5OU!c
} b(Xg6
} iROM?/$
dEL"(e#0s4
$8}'6,
/* MF(~!SOIG
**Utility.java 3%a37/|~y
*/ :.Sc[UI0
package NetFox; kl9z;(6p
k| o,gcU
![tI(TPq
public class Utility { v[ '5X
JwczE9~o
g_X7@Dt
public Utility() t1^96@m^
{ DV"ri
yBiwYk6
Nf'9]I
} Q1[s{,
?O?~|nI
//线程睡眠 bm.H0rHR4
public static void sleep(int nSecond) vsR ^aVwVZ
{ LeCU"~
try{ es]m 6A
Thread.sleep(nSecond); ,oe{@z{*@
} {`Z)'G\`
catch(Exception e) NBYE#Uih
{ PBv43uIL
e.printStackTrace (); VA.1JBQ
} }6N|+z.cU
} mY( _-[W
]H[\~J
//日志 N-]n>E
public static void log(String sMsg) <,C})H?
{ T5;D0tM/
System.err.println(sMsg); m`"s$\fah
} N~d]}J8}gx
P|U>(9;P,
Oa .%n9ec
public static void log(int sMsg) |VL,\&7rk
{ GAlO<Mu
System.err.println(sMsg); KRe=n3 1
} 0%/(p?]M
} ^D|c
H!u:P?j@\
8=9sIK2
/* "kC>EtaX
**TestMethod.java ?_r"Fg;"
*/ _K>m9Q2
package NetFox; <-pbLL9
.Dmvgi]
5KSsRq/8"
public class TestMethod { IuF-bxA
! N p
oH0\6:S
public TestMethod() )%7A. UO)
{ ///xx/weblogic60b2_win.exe enj2xye%Y
try{ zZHsS$/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2<|5zF
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [PT_y3'%
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5sE}B8 mF
fileFetch.start(); vrGNiGIi[
} }2@$2YR[
catch(Exception e){e.printStackTrace ();} :O%O``xT
=l+p nG
Yt^+31/%
} 6z*L9Vy($
qC&<U
;Z*RCuwg
public static void main(String[] args) d\f5\Y
{ LzfLCGA^
new TestMethod(); =`U[{3A_
} Cu]X&l
} L"a#Uu8
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