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)); )nS;]7pB@
} <c6C+OWT,
for(int i=0;i<nEndPos.length-1;i++) .;n<k
{ zKWcDbj
nEndPos = nStartPos[i+1]; Au,}5=+`P
} +S:(cz80V
nEndPos[nEndPos.length-1] = nFileLength; 7b,u|F
} P~:W+!@5v
} 16YJQ ue
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XH0R:+s
//启动子线程 w8(qiU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |YQ:4'^"
for(int i=0;i<nStartPos.length;i++) *IGgbg[0
{ Au"[2cG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SN'LUwaMp!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $_l@k=
nStartPos,nEndPos,i); M*E4:A9_M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2|#3rF
fileSplitterFetch.start(); :D?%!Q 0
} fdN-Zq@'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l0b Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5Y)!q?#H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o;\0xuM@
nEndPos = " + nFileLength); ?PSm) ~Oa
// fileSplitterFetch[nPos.length-1].start(); Q4Q*5>
>0i?}
~y^#?;
//等待子线程结束 >GgX-SZ%
//int count = 0; nKh._bvfX
//是否结束while循环 \p.Byso,
boolean breakWhile = false; ^C@uP9g
\A5cM\-
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while(!bStop) ZsUxO%jP
{ ~|pVz/s|G
write_nPos(); VA)3=82n
Utility.sleep(500); #=b_!~:%
breakWhile = true; ?Gj$$IAe
'sY>(D*CQ
<0R7uH
for(int i=0;i<nStartPos.length;i++) iH( K[F /
{ qw0tw2|
if(!fileSplitterFetch.bDownOver) fh )QX
{ `t:7&$>T
breakWhile = false; 3.Qf^p
break; 0:h;ots'
} 9.lSF
} KcfW+>W3
if(breakWhile) AzN.vA)q
break; v(=fV/
Rmn|"ZK
vP3Fb;
//count++; Q]w;o&eo
//if(count>4) jY:(Tv3~
// siteStop(); -t?S:9[w
} +fAAkO*GP
FI*.2rdSR
Z,,Da|edH
System.err.println("文件下载结束！"); NV*aHci
} ?9v!UT&#
catch(Exception e){e.printStackTrace ();} E`iT>+LG<
} 0X0HDQ
A,lcR:@w
lV`y6{o#T
//获得文件长度 `wB(J%w
public long getFileSize() A]BG*
{ W8yr06{]
int nFileLength = -1; E7^tU416
try{ 0d`s(b54;O
URL url = new URL(siteInfoBean.getSSiteURL()); emw3cQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;r- \h1iA'
httpConnection.setRequestProperty("User-Agent","NetFox"); >Bskw2
nrwb6wj
ECg/ge2
int responseCode=httpConnection.getResponseCode(); ilayU
if(responseCode>=400) JF%+T yMe
{ Si6%6rAhj
processErrorCode(responseCode); ?*4&Z.~J
return -2; //-2 represent access is error q'3=
} H]UM2.
4zpprh+`K
Cg}cD.
String sHeader; !7AW_l9`i
~e~4S~{
@5acTYQ
for(int i=1;;i++) G}BO!Z6
{ G:c)e,pD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N:d`L+tcc
//Utility.log(in.readLine()); x?va26FV
sHeader=httpConnection.getHeaderFieldKey(i); lsY5QE:Qrp
if(sHeader!=null) .9lx@6]+
{ {\;CGoN|
if(sHeader.equals("Content-Length")) `Kpn@Xg
{ ;8|uY%ab
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _D$|lk-
break; <3O>
} asj^K|.z
} =MB[v/M59w
else SD8Q_[rY
break; h[ba$S,T
} y''`73U"
} "CT'^d+
catch(IOException e){e.printStackTrace ();} <[8at6;
catch(Exception e){e.printStackTrace ();} `L]cJ0tAs
9{'GrL
u~bk~3.I
Utility.log(nFileLength); &P&M6v+
[,8@oM#
BV9B}IV
return nFileLength; &h`s:Y
} (O\5gAx
xl5mI~n_~
Gi6sl_"q
//保存下载信息（文件指针位置） //3iai
private void write_nPos() Cc$!TZq=
{ (}V.xi
try{ Owo2DsT t
output = new DataOutputStream(new FileOutputStream(tmpFile)); yS@c2I602
output.writeInt(nStartPos.length); &UEr4RK;I
for(int i=0;i<nStartPos.length;i++) HIk5Q'ek
{ Ha[Bf*
// output.writeLong(nPos); i!*w'[G->Y
output.writeLong(fileSplitterFetch.nStartPos); ]- ")r
output.writeLong(fileSplitterFetch.nEndPos); B~D{p t3y
} \v)Dy)Vhg2
output.close(); b" 1a7
} lr=? &>MXj
catch(IOException e){e.printStackTrace ();} "4<RMYQ
catch(Exception e){e.printStackTrace ();} &-:ZM0Fl
} M56^p,
P%8 Gaa=
X#EMmB!
//读取保存的下载信息（文件指针位置） ['~3"lK^O
private void read_nPos() yAy~|1}
{ ~pO6C*"
try{ "T=Z/@Vy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !trt]?*-
int nCount = input.readInt(); %YkJA:
nStartPos = new long[nCount]; 6}6;%{p"Gu
nEndPos = new long[nCount]; uUB,OmLN
for(int i=0;i<nStartPos.length;i++) )e d5~ok
{ [<\k
nStartPos = input.readLong(); Dt%Gv0
nEndPos = input.readLong(); 4zkn~oy
} )h]~< fU
input.close(); EiQX*v
} V(I!HT5.W
catch(IOException e){e.printStackTrace ();} 'r~,~AI
catch(Exception e){e.printStackTrace ();} ]-QY, k
} GvSSi'q~B
ZJ}9g(X..g
Px{Cvc
private void processErrorCode(int nErrorCode) ~P8 6=Vw
{ 2~dUnskyy
System.err.println("Error Code : " + nErrorCode); !~Gx@Ro
} %sxLxx_x!
Ir&rTGFN
cyrVz4_a
//停止文件下载 '#RzX8|v<
public void siteStop() 3*)<Y}Tc
{ 5$f vI#NO<
bStop = true; h DpIwzJ
for(int i=0;i<nStartPos.length;i++) cq lA"Eof
fileSplitterFetch.splitterStop(); yMaU`z
jr[(g:L
Zk,` Iq
} w0qrh\3du
} Tzr_K
//负责部分文件的抓取 1 aWzd[i
**FileSplitterFetch.java CD]hi,B_J
*/ e_RLKFv7
package NetFox; 8T6LD
KuBN_bd
?*DM|hzOi
import java.io.*; $HgBzZ7A2
import java.net.*; `9;0Y
v.iHgh
LGnb"ZN
public class FileSplitterFetch extends Thread { ] V|hDU=t
gu?e%]X3
y7CC5S?
String sURL; //File URL p7{2/mj
long nStartPos; //File Snippet Start Position I=aoP}_
long nEndPos; //File Snippet End Position LR:PSgy
int nThreadID; //Thread's ID !8g419Yg
boolean bDownOver = false; //Downing is over F/pq9
boolean bStop = false; //Stop identical rU6F$I=
FileAccessI fileAccessI = null; //File Access interface Vn&{yCm3
x,wXR=H
PP*6nW8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException EPEWyGw
{ ;R5@]Hg6q
this.sURL = sURL; -VZn`6%s
this.nStartPos = nStart; aE|'%72g
this.nEndPos = nEnd; I+oe{#:.
nThreadID = id; k8KRVXgx
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zH"a>+st=
} 5!QT }Um
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public void run() Cn"_x
{ # &,W x
while(nStartPos < nEndPos && !bStop) C/$bgK[ev
{ qt(+X
?F6L,
@V?T'@W7D
try{ ^ps6\>=0cW
URL url = new URL(sURL); A%[e<vj9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NX[-Y]t
httpConnection.setRequestProperty("User-Agent","NetFox"); _sb~eB~<(
String sProperty = "bytes="+nStartPos+"-"; Y/x>wNW
httpConnection.setRequestProperty("RANGE",sProperty); {MRXKnm;e
Utility.log(sProperty); *{_N*p\{
mEm=SpO[$o
|}7!'f\M
InputStream input = httpConnection.getInputStream(); &4O2uEW0
//logResponseHead(httpConnection); ^B_SAZ&%%
y Nc@K|
M7[GwA[Z +
byte[] b = new byte[1024]; )3IUKz%\6p
int nRead; |oWl9j]Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +v2)'?BS
{ vbD""
nStartPos += fileAccessI.write(b,0,nRead); {Gr"lOi*@
//if(nThreadID == 1) A`--*$8\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Kv9$c(~#
} zv7)JH7EV&
lak,lDt]
b'ZzDYN
Utility.log("Thread " + nThreadID + " is over!"); {?;qy\m]o
bDownOver = true; eZoAy[
//nPos = fileAccessI.write (b,0,nRead); vX7U|zy
} v8YF+N
catch(Exception e){e.printStackTrace ();} t~H0Qeb[v=
} }[{9u#@#
} yH(3 m#
~,_@|,)
}rvX}
//打印回应的头信息 Pl. y9g~
public void logResponseHead(HttpURLConnection con) n0LNAhM
{ y!dw{Lz
for(int i=1;;i++) W}y)vrL
{ cyLl,OA
String header=con.getHeaderFieldKey(i); %)72glB
if(header!=null) f|=u{6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m^\&v0
Utility.log(header+" : "+con.getHeaderField(header)); }= wor~
else 2FW"uYA;6
break; 6g\hQ\+Z}
} _s+G02/q1
} Qqi?DW1)-
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public void splitterStop() h56Kmxxk
{ =k*XGbU
bStop = true; Zb&pH~ 7
} :.tL~% q
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n|pdYe8\
} d&+0JI<
q`'"+`h
::+;PRy_E
/* '=O1n H<
**FileAccess.java D)bL;h
*//文件访问(定位，写) _-sFJi8B
package NetFox; ,a?oGi
import java.io.*; ZqdoYU'
gTgoS:M"_O
2X[oge0@
public class FileAccessI implements Serializable{ $Mj\ 3
w[D]\>QHa
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ' tHa5`
RandomAccessFile oSavedFile; kMK0|+
long nPos; /Wcx%P
u}%6=V
zd)QCq
public FileAccessI() throws IOException "OA{[)fw"
{ |`?&
this("",0); j#2EQ
} %LzARTX
UlXxG|
1og+(m`BL
public FileAccessI(String sName,long nPos) throws IOException WR`NISSp
{ %k32:qe
oSavedFile = new RandomAccessFile(sName,"rw"); ;gZ/i93:Q
this.nPos = nPos; kxd*B P
oSavedFile.seek(nPos); a;^lOU|L{
} ."=p\:^j*
r#2Fk&Z9
zeuj
public synchronized int write(byte[] b,int nStart,int nLen) !zx8I7e4
{ <K<#)mcv
int n = -1; AoOA.t6RVo
try{ \lm]G7h
oSavedFile.write(b,nStart,nLen); q^sZP\i,*;
n = nLen; jwAYlnQ^EM
} .gmS1ju
catch(IOException e) T@i* F M
{ kE.4 #
e.printStackTrace (); NU?<bIQ
} "O0xh_Nr
!&hqj$>-}
N) _24
return n; k_,& Q?GtU
} ni%)a
[2Zy~`*y{
-,b+tC<V)0
} `R:W5_n
z)U7
w-# f^#
/* DE/SIy?
**SiteInfoBean.java \>Rfa+
*/ Z:7eroZP
package NetFox; 'UWkJ2:!
+Tu?PuT7k
SU4i'o
public class SiteInfoBean { J](NCD
irD5;xk([
6V]m0{:E
private String sSiteURL; //Site's URL ERIMz,
private String sFilePath; //Saved File's Path =hFY-~U
private String sFileName; //Saved File's Name f+uyO7
private int nSplitter; //Count of Splited Downloading File g,EDE6`8
@QVg5
]&]DFY~n
public SiteInfoBean() +71<B>L
{//nSplitter的缺省值为5 wCNn/%C
//default value of nSplitter is 5 <JWU@A-.y
this("","","",5); JOY&YA$U
} zU~ Ff"<
N=<`|I
i83~&Q=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) McasnjC
{ M['O`^
sSiteURL= sURL; =;uMrb4
sFilePath = sPath; [5?Dov^j3
sFileName = sName; 8(\}\4G_
this.nSplitter = nSpiltter; (b f IS
oc( '!c
Mg`!tFe3
} )&j`5sSXcr
F&czD;F
"Bf8mEmp
public String getSSiteURL() 3Xu|hkK\e
{ hbx4[Pf
return sSiteURL; y ;[~(Yg[
} vw2E$ya
1 6zxPSTr}
05FGfnq.8
public void setSSiteURL(String value) .u7}p#
{ AuXUD9-
sSiteURL = value; !t23 _b0
} [G|.
eW(pP>@k,
1WMZ$vsQUb
public String getSFilePath() H:~p5t
{ k=mQG~
return sFilePath; b}R_@_<u
} \yJ 4+vo2Q
p<r<Y%
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public void setSFilePath(String value) :.*Q@X}-I
{ -iDs:J4Iq
sFilePath = value; (WT\HR
} +x 3x
dP8qP_77A~
OCx'cSs-=
public String getSFileName() })-V,\
{ , lR(5ZI
return sFileName; z[c8W@OJ
} Pw<?Dw]m
$#hU_vr
F+H]{ss>
public void setSFileName(String value) d%P2V>P
{ }+KM"+@$<
sFileName = value; 9A.NM+u7
} %"H:z
S5hc@^|0Z
}h;Z_XF&
public int getNSplitter() -w"I
{ ]"T157F
return nSplitter; swj\X,{
} !}*vM@)1
u* pQVU
H>/,Re
public void setNSplitter(int nCount) LG,?,%_s
{ ,9ueHE
nSplitter = nCount; =cl#aS}e8
} aftt^h
} )W\)kDh!
RDbNC v#
AJ/Hw>>$?m
/* 2@a'n@-
**Utility.java Hi[lN7ma8
*/ [s^pP2
package NetFox; U=D;CjAh
i`@cVYsL
oqwW
public class Utility { c:K/0zY
PJB_"?NTTC
=r/K#hOR\J
public Utility() )$^xbC#j`3
{ q,fp DNo
qY-aR;
&;ddnxFI
} ByjfPb#
YTTy6*\,_
//线程睡眠 KN_n:`cH{
public static void sleep(int nSecond) ^iEf"r
{ h:Gs9]Lvtv
try{ c= 2E/x?
Thread.sleep(nSecond); {@KLN<
} :gRrM)n
catch(Exception e) ;,U@zB;\%(
{ EO+Ix7w
e.printStackTrace (); e[x,@P`
} 1<@lM8&.kO
} _\4r~=`HQ
9*iVv)jd
//日志 MDa[bQNM
public static void log(String sMsg) 6p;Pf9 f
{ /w dvm4
System.err.println(sMsg); BpA7 z/
} ("A45\5
kN 2mPD/
v0WB.`rO
public static void log(int sMsg) vH6(p(l
{ A["6dbvv
System.err.println(sMsg); G{.=27
} 2pHR$GZ2
} ,FYA*}[
1;./e&%%
t`&mszd~T
/* d+P<ce2G
**TestMethod.java bg3kGt0
*/ LkeYzQH/l
package NetFox; dh}"uM}a
$m>( kd1
i{:?Iw 'ay
public class TestMethod { lKQjG+YF
8fvKVS
5Q}HLjG8Z
public TestMethod() ;,/G*`81B
{ ///xx/weblogic60b2_win.exe 1jSmTI d
try{ S% ptG$Z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ! ,]Fx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V'.gE6we
SiteFileFetch fileFetch = new SiteFileFetch(bean); VKXB)-'L
fileFetch.start(); {>R933fap
} |<]wM(GxE
catch(Exception e){e.printStackTrace ();} DS|x*w'I
/$8& r
*}r6V"pH~
} Nde1`W]:
Oa5-^&I
^y&2N
public static void main(String[] args) dZ,7q_r,~
{ Dxr4B<
new TestMethod(); ^SUo-N''
} h1j1PRE
} -RThd"
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