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)); /:-8 ,`
} *_Y{wNF*
for(int i=0;i<nEndPos.length-1;i++) dW hU o\>=
{ e C\;n
nEndPos = nStartPos[i+1]; [kfLT::mT
} nt$VH
nEndPos[nEndPos.length-1] = nFileLength; Jb. V4
} \^7D%a=;C
} $]eU'!2)
obYXDj2
3C8cvi[IS
//启动子线程 <PCa37
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N%8O9Dp8;
for(int i=0;i<nStartPos.length;i++) 6I,^4U
{ !JZ)6mtlr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4.?tP7UE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tPDd~fOk
nStartPos,nEndPos,i); ZaxBr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \UKr|[P
fileSplitterFetch.start(); {(o$? =
} QFn .<@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9 F"2$;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R*m=V{iu`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZHQa}C+
nEndPos = " + nFileLength); ZbS*zKEW
// fileSplitterFetch[nPos.length-1].start(); eUa2"=M
& ,KxE(C
nJEm&"AI
//等待子线程结束 zR)9]pJ-
//int count = 0; ^zdZ"\x
//是否结束while循环 lJe=z
boolean breakWhile = false; 7WuhYJbf
nYfZ[Q>v
;xp^FKP
while(!bStop) xW`,@a}
{ B2}|b^'I
write_nPos(); MoIq)5/
Utility.sleep(500); 6rBXC <Z
breakWhile = true; FQc8j:'
F(?A7
q-3,p.
for(int i=0;i<nStartPos.length;i++) <F~0D0G
{ s\7]"3:wD
if(!fileSplitterFetch.bDownOver) 2m$\]\kCUv
{ dd$}FlT
breakWhile = false; RtE2%d$JT
break; @"B"*z-d
} t-, =sV
} e.8(tEqZ1
if(breakWhile) cjTV~(i'4A
break; 1 uKWvp0\
8SJi~gV
zOV.cI6fZz
//count++; fT:a{
//if(count>4) _]g?3Gw7!
// siteStop(); ]!v:xjzT
} "JHdF&
@wzzI 7}C
m[k@\xS4e
System.err.println("文件下载结束！"); 5]c'n
} TB!z:n
catch(Exception e){e.printStackTrace ();} 4 w$f-
} L=Pz0
?b}d"QsmU
W7k0!Grrl
//获得文件长度 ncF|wz
public long getFileSize() SHc<`M'+
{ >= G{.H
int nFileLength = -1; %xa.{`}`U
try{ Oa8lrP`(
URL url = new URL(siteInfoBean.getSSiteURL()); 6/A#P$G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -#9Hb.Q;
httpConnection.setRequestProperty("User-Agent","NetFox"); x4r=ENO)q
Py&DnG'H
XN*?<s3
int responseCode=httpConnection.getResponseCode(); #u<^
if(responseCode>=400) .Mn+Bd4f
{ c^4^z"Mo`
processErrorCode(responseCode); X=sC8Edx
return -2; //-2 represent access is error 1;e"3x"
} ??4#)n k
M9_G
E3p3DM0F$
String sHeader; /b$0).fj@,
~v /NG
BdK2I!mm
for(int i=1;;i++) $r>\y (W
{ j@j%)CCM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *@EItj`
//Utility.log(in.readLine()); b1("(,r/`
sHeader=httpConnection.getHeaderFieldKey(i); y<53xZi
if(sHeader!=null) p1-bq:
{ )]\?Yyg]
if(sHeader.equals("Content-Length")) vf|lF9@U
{ ,b&-o?.{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )_MIUQ%
break; %lr<;
} 9JG9;[
} R%(ww
else `|["{j}^
break; #[4MwM3
} ]m>N!Iu
} ~miRnW*x
catch(IOException e){e.printStackTrace ();} (Wj2%*NT
catch(Exception e){e.printStackTrace ();} |L@9qwF
dzK]F/L]
Z5oX "Yx
Utility.log(nFileLength); QGWfF,q
Eyv|~D
Ab"mX0n
return nFileLength; bZ/4O*B
} $IuN(#
MzF9 &{N
}G:5P3f
//保存下载信息（文件指针位置） f;Iaf#V_
private void write_nPos() q,<AW>
{ Ws+Zmpk%
try{ *zf@J'
output = new DataOutputStream(new FileOutputStream(tmpFile)); AADvk_R
output.writeInt(nStartPos.length); L$ nFRl&
for(int i=0;i<nStartPos.length;i++) vPVA^UPNV
{ Gk.;<d
// output.writeLong(nPos); cY}Nr#%s@U
output.writeLong(fileSplitterFetch.nStartPos); 6Y#V;/gK!5
output.writeLong(fileSplitterFetch.nEndPos); !k=>Wb8n2
} m4U7{sE
output.close(); [jOvy>2K]
} 8?n6\cF
catch(IOException e){e.printStackTrace ();} xk1pZQ8c
catch(Exception e){e.printStackTrace ();} W|go*+`W%
} t`"]"Re
m[@7!.0=
$] js0)>
//读取保存的下载信息（文件指针位置） &"90pBGK
private void read_nPos() U9om}WKO
{ B{D!5{t
try{ &DqeO8?Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n..9F$a
int nCount = input.readInt(); \XG18V&
nStartPos = new long[nCount]; nFVQOr;
nEndPos = new long[nCount]; wYf9&}k\4
for(int i=0;i<nStartPos.length;i++) =4;GIiF@
{ H:~41f[
nStartPos = input.readLong(); K1P3 FfG
nEndPos = input.readLong(); )8H5ovj.
} n9J.]+@J
input.close(); J,8Wo6
} xK`.^W
catch(IOException e){e.printStackTrace ();} </K"\EU
catch(Exception e){e.printStackTrace ();} |JpLMUG
} QfI)+pf
G3j&8[
NFc@Kz<H
private void processErrorCode(int nErrorCode) Y)x(+#
{ T~nmEap
System.err.println("Error Code : " + nErrorCode); htn"rY(
} xDf<@
IC-k
zc<C %t[~y
//停止文件下载 WQ\H2go
public void siteStop() ZMSP8(V
{ MPMa
bStop = true; 7Y:~'&U|
for(int i=0;i<nStartPos.length;i++) "z `&xB
fileSplitterFetch.splitterStop(); UB3b
LL~bq(b
8:j8>K*6
} 4v+4qyMyE
} K-$gTV
//负责部分文件的抓取 ~-+lZ4}
**FileSplitterFetch.java $<)k-Cf
*/ :)GtPTD
package NetFox; 1D /{Y
M(,npW
*o8DfZ
import java.io.*; P:z5/??2S
import java.net.*; O87Ptr8
0K-jF5i$`
<r*A(}Y
public class FileSplitterFetch extends Thread { Y4PB&pZ$O2
w5I +5/I
+jcg[|-'/
String sURL; //File URL W/O&(t
long nStartPos; //File Snippet Start Position W/PZD (
long nEndPos; //File Snippet End Position Nl_Sgyx,\
int nThreadID; //Thread's ID tqY)
boolean bDownOver = false; //Downing is over O!!Ne'I
boolean bStop = false; //Stop identical z}'*zB>
FileAccessI fileAccessI = null; //File Access interface J4 yT|
*$nz<?
#D"fCVIS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;Ry )^5Q
{ z5CZ!"&v
this.sURL = sURL; q9j9"M'
this.nStartPos = nStart; Z:|2PQ4
this.nEndPos = nEnd; hB#z8D
nThreadID = id; eATX8`W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pIh%5ZU
} [c@14]e
K (yuL[p`
]XEkQ
public void run() N 3)OH6w"
{ *pN,@ZV$
while(nStartPos < nEndPos && !bStop) Ws[[Me,=
{ <$s G]l!\
8$!/Zg
!m"(SJn"
try{ G`NH~C
URL url = new URL(sURL); ^a@Vn\V1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QKYGeT7&Y'
httpConnection.setRequestProperty("User-Agent","NetFox"); iYj+NL
String sProperty = "bytes="+nStartPos+"-"; ^'DrU<o
httpConnection.setRequestProperty("RANGE",sProperty); {5U;9: sO6
Utility.log(sProperty); 'z\K0
zV {[0s
q2}<n'o+
InputStream input = httpConnection.getInputStream(); ~:."BA
//logResponseHead(httpConnection); mqGp]'{
|y@TI
e.eQZ5n~q`
byte[] b = new byte[1024]; )J+vmY~&
int nRead; 0(VQwGC[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u]P0:)tS.
{ vkan+~H
nStartPos += fileAccessI.write(b,0,nRead); *ms?UFV[r
//if(nThreadID == 1) IMzhEm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5Bw
} o>{+vwK
'sI=*c
xz YvD{>
Utility.log("Thread " + nThreadID + " is over!"); +x$;T*0
bDownOver = true; D,+I)-k<
//nPos = fileAccessI.write (b,0,nRead); vyT$IdV2
} )K\w0sjR
catch(Exception e){e.printStackTrace ();} .H+`]qLkL
} NS"hdyA
} O&]Y.Z9,A
m*h d%1D
XiI@Px?FL
//打印回应的头信息 ]SpUD
public void logResponseHead(HttpURLConnection con) |{HtY
{ C^RO@kM
for(int i=1;;i++) $@q)IK%FDL
{ ,dKcxp~[
String header=con.getHeaderFieldKey(i); *nDyB.(
if(header!=null) [Z0&`qz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #X7fs5$&
Utility.log(header+" : "+con.getHeaderField(header)); /AWV@'
else J\XYUs
break; 3+"z
} ?f[#O&#
} eu~WFI
YVZm^@ZVV
y!fV+S,
public void splitterStop() g+p?J.+
{ Ph2jj,K
bStop = true; #)_4$<P*'
} XX~~SvSM
30g-J(Zg
CD%wi:C%|
} w<N[K>
l,HMm|oU
Lllyx20U
/* 2J9_(w
**FileAccess.java tlu-zUsi
*//文件访问(定位，写) &H;0N"Fn
package NetFox; 828E^Q"<
import java.io.*; UyBI;k^]
+j&4[;8P:
_!H{\kU
public class FileAccessI implements Serializable{ [Hy0j*
$`x4|a8-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wgpu]ooUF&
RandomAccessFile oSavedFile; M?x/C2|
long nPos; ~\<Fq\.x
g5lf-}?
mu04TPj
public FileAccessI() throws IOException $0V<wsVM
{ DY'D]*'7$
this("",0); 8-UlbO6
} X0+$pJ60
K/KZ}PI-O
d%NO_=I.
public FileAccessI(String sName,long nPos) throws IOException 4a00-y='
{ 4!,x3H'
oSavedFile = new RandomAccessFile(sName,"rw"); _dVzvk`_R
this.nPos = nPos; _5EM<Ux
oSavedFile.seek(nPos); -("sp
} cU?A|'
Co&#mVY4,
fI;6!M#
public synchronized int write(byte[] b,int nStart,int nLen) Zsc710_
{ *=mtt^yZ
int n = -1; b=horvs/!
try{ m!SxX&m"G
oSavedFile.write(b,nStart,nLen); f/&gR5
n = nLen; "C&l7K;bp
} ,<0R'R
catch(IOException e) wO/}4>\
{ w2_$>z
e.printStackTrace (); n|sP0,$N1
} ET;YAa*
u6Fm qK]Dj
ozwPtF5
return n; CtJ*:wF
} rrbD0UzFA
P~`gWGC}
{z>fe }
} ?XN=Er^
`ECT8
_b|mSo,{Y
/* 4v9jGwnzt
**SiteInfoBean.java kKL'rT6z
*/ X)^eaw]Q0
package NetFox; o~<Xc
Q46^i7=
pW$ZcnU
public class SiteInfoBean { 9oBK(Sf@^
UgI0 *PE2
`Cq&;-u
private String sSiteURL; //Site's URL +9Q,[)e r
private String sFilePath; //Saved File's Path V&)Jvx}^
private String sFileName; //Saved File's Name :0N}K}
private int nSplitter; //Count of Splited Downloading File " E+V>V+
Sv3O${B|
@9#l3
public SiteInfoBean() z7TMg^9#
{//nSplitter的缺省值为5 kq|(t{@Rp
//default value of nSplitter is 5 DS;,@$N_N
this("","","",5); JC6?*R
} Nl/^ga
wT\JA4
x6yYx_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) En!X}Owh
{ E$O-\)wY0
sSiteURL= sURL; #<h//<
sFilePath = sPath; >u?m Bx
sFileName = sName; 5<64 C}fE3
this.nSplitter = nSpiltter; xf2|9Tqt
NJ]AxFG
vq?Lej
} ri.}G
-sjyv/%_
ZZ'5BfI"I%
public String getSSiteURL() |k.%e4
{ kg&R
return sSiteURL; T'6MAxEZUq
} 6LRvl6ik
p~Wy`g-
8MQb5( !
public void setSSiteURL(String value) ~fnu;'fN
{ (>.lkR
sSiteURL = value; <n1panS
} &&PXWR!%]
X!xmto
33},lNS|
public String getSFilePath() 8 $qj&2 N
{ ldFR%v>9
return sFilePath; !jWE^@P/B
} AZ.$g?3w
'fjouO
xmNs%
public void setSFilePath(String value) q0C%">>1#
{ zq(4@S-TU
sFilePath = value; FUVp}>#U
} X$2f)3
:%-w/QwTR
H)k V8wU
public String getSFileName() .H@b zm
{ (kTu6t*
return sFileName; 5) q_Aro
} $\+x7"pI
,njlKkFw^Z
NkV81?
public void setSFileName(String value) W3zYE3DZf
{ ZEK,Z['
sFileName = value; UgLFU#
} I&U.5wf
1xEFMHjy
lc8g$Xw3
public int getNSplitter() '%X29B5
{ + \]-"
return nSplitter; uBK0+FLL@
} 7gcR/HNeF
+MZI\>
uPq@6,+
public void setNSplitter(int nCount) Lf)JO|o
{ jddhX]>I
nSplitter = nCount; w4fQ~rcUIc
} DRpFEWsm
} *c\XQy
dF[|9%)
%JHv2[r^P
/* '?jsH+j+
**Utility.java Z3yy(D>*
*/ t`="2$NO
package NetFox; l$Vy\CfK3n
&09&;KJ
!Rc %
public class Utility { 5E]iv^q%
b}DC|?~M
}hsNsQ
public Utility() E~#G_opQA
{ soLW'8
Y0Tad?iC
lu00@~rx/
} +HPcvu?1
q 'd]
//线程睡眠 }K={HW1>
public static void sleep(int nSecond) oNIYO*[
{ PZQAlO,
try{ z{|0W!nHJ
Thread.sleep(nSecond); UWnF2,<s;
} \gA<yz-;N
catch(Exception e) D+v?zQw
{ m94PFD@N
e.printStackTrace (); f=k#o2
} IA<>+NS
} yuy\T(7BN
%L^(eTi[
//日志 <$yA*
public static void log(String sMsg) >SLQW
{ 5q*s_acQ
System.err.println(sMsg); :A zlls
} +WAkBE/
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rH!sImz,
public static void log(int sMsg) >t.Lc.
{ z &Xl
System.err.println(sMsg); G"` }"T0}
} (BPO*'
} CV\^gTPmx
"o+?vx-
41Z@_J|&
/* C{}PO u
**TestMethod.java <#ON
*/ ^7wqb'xg
package NetFox; !p/SX>NJ
)M.s<Y
{Y@shf;
public class TestMethod { Et!J*{s
l>K+4
&muBSQ-
public TestMethod() /M%>M]
{ ///xx/weblogic60b2_win.exe \894Jqh
try{ h\UKm|BZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F$)l8}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,eBC]4)B6
SiteFileFetch fileFetch = new SiteFileFetch(bean); CdF;0A9.3
fileFetch.start(); O\.^H/
} l<w7 \a6
catch(Exception e){e.printStackTrace ();} udqrHR5
Q3tyK{JE
D#L(ZlD4
} /Ne#{*z)hO
{/]2~!
I8?
public static void main(String[] args) ySr,HXz
{ B^/MwD>%
new TestMethod(); wHbkF#[:i
} 4`Ud\Jm[s
} 3A!a7]fW
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