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)); 6Xjr0C+
} I("J$
for(int i=0;i<nEndPos.length-1;i++) .\0PyV(
{ &n% 3rC5{
nEndPos = nStartPos[i+1]; `(|jm$Q
} ,q yp2Y7
nEndPos[nEndPos.length-1] = nFileLength; |w(@a:2kw
} wo;`D
} @u./VK
d%$'Y|
Y'NQt?h
//启动子线程 C7ZU)MEUd/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; LTsG
for(int i=0;i<nStartPos.length;i++) e[t+pnRh
{ kLKd O0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dP(*IOO.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K!q:A+]
nStartPos,nEndPos,i); 1mw<$'pm0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~=5vc''
fileSplitterFetch.start(); X@u-n_
} mZVYgJQ[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /cBQE=]6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ju$vuEO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hSmu"a,S
nEndPos = " + nFileLength); D.2HM
// fileSplitterFetch[nPos.length-1].start(); 56Q9RU(M
pq`Bg`c
8=^o2&
//等待子线程结束 MtAD&+3$
//int count = 0; m/"\+Hv
//是否结束while循环 jI$}\*g
boolean breakWhile = false; * %p6+D-C
sF?N vp
v*Qr(4
while(!bStop) i[b?W$]7
{ U@$Kp>X
write_nPos(); gk+$CyjJ
Utility.sleep(500); Xp]tL3-p
breakWhile = true; *N"bn'>3
T,h,)|:I^
P7n+@L$
for(int i=0;i<nStartPos.length;i++) &Y2mLPB
{ GI}h)T
if(!fileSplitterFetch.bDownOver) pPcn F`A
{ <!h&h
breakWhile = false; bdiyS.a-
break; o6^^hc\
} "M*Pt
} +>N/q(l
if(breakWhile) \*#9Ry^f
break; UOrfwK
>= Hcw
36D-J)-Z
//count++; ^a@Vn\V1
//if(count>4) X*Mw0;+T
// siteStop(); v>TI.;{y
} dB7E&"f
/IM5#M5~
sa8Sy&X"
System.err.println("文件下载结束！"); 24 S,w>j
} t@-:e^ v
catch(Exception e){e.printStackTrace ();} I(r^q"
} [o)P
J;Az0[qMR
&UG7 g
//获得文件长度 O?omL5
public long getFileSize() 372ewh3'
{ jyPY]r
int nFileLength = -1; \[&~.B
try{ >a98H4
URL url = new URL(siteInfoBean.getSSiteURL()); SE+K"faKQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :0Nd4hA
httpConnection.setRequestProperty("User-Agent","NetFox"); iulM8"P
TL(L[
KYY~ YP
int responseCode=httpConnection.getResponseCode(); v2 [ l$
if(responseCode>=400) #;'1aT
{ _N~h#(
processErrorCode(responseCode); H"8+[.xBh
return -2; //-2 represent access is error kStWsc$;+T
} B[F,D
>\b=bT@iM
=)C}u6
String sHeader; ( q^umw
o>{+vwK
XA{tVh
for(int i=1;;i++) -\@&^e
{ [#H$@g|CT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Zs!)w9y&V
//Utility.log(in.readLine()); ;pdW7
sHeader=httpConnection.getHeaderFieldKey(i); :Vq gmn
if(sHeader!=null) $~4ZuV%
{ v"Bv\5f,Ys
if(sHeader.equals("Content-Length")) b w5|gmO
{ 6/9 A'!4C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [vpZ3;
break; &;7\/m*W1
} V0R;q
} 5I5~GH
else Dm6WSp1|b
break; N4"%!.Y
} C^RO@kM
} elXY*nt8h
catch(IOException e){e.printStackTrace ();} <1]#E@
catch(Exception e){e.printStackTrace ();} !G3O!]
"2(4?P
yB(^t`)}N
Utility.log(nFileLength); oQ@X}6B%S
q%#dx4z&
3/o-\wWO
return nFileLength; sj003jeko
} rixNz@p'%
~q#UH'=%
zLuej'
//保存下载信息（文件指针位置） Zr'VA,v
private void write_nPos() ihKnZcI$i
{ y1^<!I
try{ RH^8"%\
output = new DataOutputStream(new FileOutputStream(tmpFile)); mKynp
output.writeInt(nStartPos.length); +](^gaDw<L
for(int i=0;i<nStartPos.length;i++) ~h?zK1
{ oT$w14b
// output.writeLong(nPos); 6Km@A M]
output.writeLong(fileSplitterFetch.nStartPos); G_=`&i"4
output.writeLong(fileSplitterFetch.nEndPos); R`Hyg4?
} -uN5DJSW
output.close(); LX4S}QXw
} _OP75kv
catch(IOException e){e.printStackTrace ();} S/]2Qt#T
catch(Exception e){e.printStackTrace ();} erYpeq.
} *nU7v3D
d@pD5n=m;
5[[4A]#T
//读取保存的下载信息（文件指针位置） ^3IO.`|
private void read_nPos() $@[6jy
{ i;`rzsRb
try{ FVsVY1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8vK Z;
int nCount = input.readInt(); $d%m%SZxv
nStartPos = new long[nCount]; )Ve?1?s '8
nEndPos = new long[nCount]; He. gl
for(int i=0;i<nStartPos.length;i++) $/nU0W
{ YY{S0jnhF
nStartPos = input.readLong(); FkR9-X<
nEndPos = input.readLong(); z#GZvB/z)
} =yOIP@
input.close(); =9FY;9
} [F%INl-sy
catch(IOException e){e.printStackTrace ();} n !]_o
catch(Exception e){e.printStackTrace ();} dGf{d7D
} G%-[vk#]
Af1mTbf=
i[@*b/A
private void processErrorCode(int nErrorCode) {e0cc1Up}
{ 6;9SU+/
System.err.println("Error Code : " + nErrorCode); Xa\{WM==;
} HlgF%\@a+U
4StiYfae
|Spy |,/
//停止文件下载 DY'D]*'7$
public void siteStop() ,ClGa2O
{ N^xnx<
bStop = true; ?SRG;G1
for(int i=0;i<nStartPos.length;i++) K/KZ}PI-O
fileSplitterFetch.splitterStop(); 6:i{_YX(.S
7NV1w*>/
L|EvI.f
} a,x-akZWf
} L0Bcx|)"$`
//负责部分文件的抓取 w4<1*u@${
**FileSplitterFetch.java %fnL
*/ 6%~ Z^>`N
package NetFox; (eS4$$g
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M%5qx,JQY
import java.io.*; nAG2!2_8
import java.net.*; R2yiExw<
(e6JI]tz{
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public class FileSplitterFetch extends Thread { Tn< <i
uV`r_P
5Jh=${
String sURL; //File URL ='a[(C&Y
long nStartPos; //File Snippet Start Position @v\Osp t=
long nEndPos; //File Snippet End Position `WGT`A"
int nThreadID; //Thread's ID x hBlv
boolean bDownOver = false; //Downing is over pca `nN!
boolean bStop = false; //Stop identical <43O,Kx'Su
FileAccessI fileAccessI = null; //File Access interface "VR>nyG%
.z4 fJx
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r) ;U zd
{ n=WwB(}q
this.sURL = sURL; <SGO+1ztp
this.nStartPos = nStart; O{SP4|0JV
this.nEndPos = nEnd; <V0]~3
nThreadID = id; '`&gSL.1a@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w4P?2-kB
} .w/w] Eq
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rg64f'+Eug
public void run() Y|FF ;[
{ q}p&<k
while(nStartPos < nEndPos && !bStop) q@8Jc[\d
{ N]udZhkn
6^y*A!xY
xCGa3X
try{ j\k|5="w-
URL url = new URL(sURL); W5PNp%+KE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9z6-HZG'~<
httpConnection.setRequestProperty("User-Agent","NetFox"); u:JD
String sProperty = "bytes="+nStartPos+"-"; P|HxD0c^u
httpConnection.setRequestProperty("RANGE",sProperty); e=&,jg?K
Utility.log(sProperty); 8Q ba4kgL
88x_}M^Fnl
Ndq/n21j
InputStream input = httpConnection.getInputStream(); 1Kszpt(Ld
//logResponseHead(httpConnection); d"o5uo
rT7W_[&P
WyciIO1
byte[] b = new byte[1024]; lHQ:LI
int nRead; `,a6su (?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 67/JsL
{ no_;^Ou?
nStartPos += fileAccessI.write(b,0,nRead); Z> Jm
//if(nThreadID == 1) .P(k |D&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W|h~&O
} dJxdrs
G(gJtl
m_YXTwwx
Utility.log("Thread " + nThreadID + " is over!"); ~SUrbRaY>
bDownOver = true; z#9Tg"8]
//nPos = fileAccessI.write (b,0,nRead); }zC9;R(E
} U|SF;T .
catch(Exception e){e.printStackTrace ();} n'*4zxAA
} 2q]y(kW+
} )tYu3*'
" E+V>V+
Cge@A'2
//打印回应的头信息 GPV=(}z
public void logResponseHead(HttpURLConnection con) &iKy
{ =`Ii?xo
for(int i=1;;i++) z7TMg^9#
{ Io_bS+
String header=con.getHeaderFieldKey(i); 8'XAZSd(
if(header!=null) z5.Uv/n\1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v2eLH:6
Utility.log(header+" : "+con.getHeaderField(header)); :jL>sGvBv
else q[?xf3
break; h [*/Tnr
} `%S 35x9
} "y~tAg
fghw\\]3
)&/ecx"2Q
public void splitterStop() g{PEplk
{ E$O-\)wY0
bStop = true; -YvnX0j+
} !UHWCJ< <w
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xf2|9Tqt
} 7m.#No>^
yuP1*QJ%
1N\/61+aA
/* rfo7\'yk
**FileAccess.java m&S *S_c
*//文件访问(定位，写) suKr//_
package NetFox; $?P5A E
import java.io.*; [G!#y
hp|.hN(kS]
P^'TI[\L9
public class FileAccessI implements Serializable{ :/A7Z<u,
Ymvd3>_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a+mrsyM
RandomAccessFile oSavedFile; iYaS
long nPos; *Wj]e%
N!~O~Eo3
'ug:ic
public FileAccessI() throws IOException deLLqdZa
{ w'uB&z4'
this("",0); 6W\G i>
} q4MR9ig1E_
{,NF'x4$
[?>\]
public FileAccessI(String sName,long nPos) throws IOException s5s'[<
{ -v %n@8p
oSavedFile = new RandomAccessFile(sName,"rw"); px${ "K<
this.nPos = nPos; .9NYa|+0
oSavedFile.seek(nPos); n2A ; `=
} iW%~>`tT
i(qZ#oN
X'uQr+p^
public synchronized int write(byte[] b,int nStart,int nLen) G)8v~=Bv
{ T W#s)iDi
int n = -1; `!(IQ&
try{ J?#Xy9dz
oSavedFile.write(b,nStart,nLen); MCO2(E-
n = nLen; ,ZV>"'I:
} ?lca#@f(
catch(IOException e) AZ.$g?3w
{ WAt=T3
e.printStackTrace (); LvqWA}
} )FpizoVq0
a%nf )-}|
dtj+ avG
return n; {8* d{0l
} @WCA7DW!
}]i.z:7+
FG!2h&k
} |:w)$i& *
I>EEUQR/$H
^UCH+Cyl
/* oGRd ;hsF
**SiteInfoBean.java 6gs0Vm
*/ 6Ki!j<
package NetFox; [H[L};%=j
KAJR.YNm
5) q_Aro
public class SiteInfoBean { ^c<8|lK L@
r;^%D(
j7BLMTF3v
private String sSiteURL; //Site's URL VUi> ]v/e
private String sFilePath; //Saved File's Path )+Y"4?z~
private String sFileName; //Saved File's Name =PF2p'.o
private int nSplitter; //Count of Splited Downloading File hd*GDjmRQ/
B:Y F|k}T
W{%X1::q$
public SiteInfoBean() Vk> &
{//nSplitter的缺省值为5 B*(BsXQLY
//default value of nSplitter is 5 QWc,JCu
this("","","",5); xa'^:H $X
} $cWt^B'
%*NED zy
-7KoR}Ck!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P;`Awp?
{ jF-:e;-
sSiteURL= sURL; &,P; 7R
sFilePath = sPath; a&2UDl%K
sFileName = sName; I_m3|VCa|t
this.nSplitter = nSpiltter; c@2a)S8Y]
G@KDRv
7B<,nKd
} : *XAQb0
ypgM&"eR
M1]}yTCd
public String getSSiteURL() R< L =&I
{ w4fQ~rcUIc
return sSiteURL; hFo29oN
} riL|B3
x6)qs-
d>?C?F
public void setSSiteURL(String value) 9Fy'L#%
{ Z3yy(D>*
sSiteURL = value; #*q]^Is"
} nG";?TT
P!"{-m'
Q*Y-@lZ
public String getSFilePath() &09&;KJ
{ ?nPG#Z|%
return sFilePath; X}xf_3N "
} 0 *;i]owV
{cUGksz]}
b}DC|?~M
public void setSFilePath(String value) gW<6dP'v
{ qyxd9Lk1
sFilePath = value; Gy[anDE&
} m_;fj~m
soLW'8
q9dplEe5
public String getSFileName() Zs]n0iwM'@
{ {sf ,(.W
return sFileName; gxhdxSm=2
} +HPcvu?1
R`Fgne$4
Zf1 uK(6X
public void setSFileName(String value) *;)O'|
{ ZH|q#<{l
sFileName = value; 2{.g7bO
} < =~=IZ)
2WDe34
/* qx5$~
public int getNSplitter() H[nco#
{ tkH]_cH'w
return nSplitter; g^Hf^%3xP
} /@|iI<|
UWnF2,<s;
}AA">FF'y4
public void setNSplitter(int nCount) %*szB$[3
{ X4]miUmh
nSplitter = nCount; 4Z>gK(
} Gh/nNwyu<
} qFK.ULgP`
ht*(@MCr<
\i/HHP[%
/* =%<, ^2o
**Utility.java eM{u>n+`F0
*/ "AZ|u#0P
package NetFox; !qp$Xtf+
7)]boW~Q
\I:27:iAL
public class Utility { P JATRJ1.
Pn^`_
nShXY6bA
public Utility() pbEWnx_
{ _}Qtx/Cg
p5$}h,7
[.^ol6
} &9^4-5]
Pc*lHoVL
//线程睡眠 p:TE##
public static void sleep(int nSecond) }ymW};W
{ Zj!,3{jX^
try{ "5L?RkFi\
Thread.sleep(nSecond); >t.Lc.
} %'ah,2a%
catch(Exception e) '5Yzo^R;
{ f*<Vq:N=\
e.printStackTrace (); HA8A}d~
} \#(1IC`as
} SGSyO0O
YTFU#F
//日志 26g]_Igq
public static void log(String sMsg) %-yzU/`JF
{ ; ?f+
System.err.println(sMsg); F$DA/{.D
} 4VZI]3K,
,+ G
t$(#$Z,RS
public static void log(int sMsg) CDM6o!ur3
{ _\KFMe=PV
System.err.println(sMsg); WM`3QJb
} COsmVQ.
} d_d&su E
gkO^J{_@q
~1D^C |%
/* r) x
**TestMethod.java W,NqevXo:
*/ `X5!s
package NetFox; jhm/<=
BW7AjtxQ&
a51e~mg Z`
public class TestMethod { F$)l8}
2PYnzAsl
;O% H]oN
public TestMethod() \KnRQtlI
{ ///xx/weblogic60b2_win.exe @JXpD8jn
try{ O\.^H/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %h@1lsm1+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q@~g.AMCB
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'KA$^
fileFetch.start(); 4?1Qe\A^
} !nSa4U,$w<
catch(Exception e){e.printStackTrace ();} 8j;Un]
M i& ;1!bg
]B,tCBt
} >Xk42zvqn
v']_)
6&os`!
public static void main(String[] args) `jGeS[FhR
{ xcr2|
new TestMethod(); qg& /!\
} EjLq&QR.
} a*y9@RC}
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