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)); VI" ,E}
} =2J+}ac
for(int i=0;i<nEndPos.length-1;i++) ,0lRs
{ sGMC$%e}
nEndPos = nStartPos[i+1]; "o;l8$)VL
} X*$ 7g;
nEndPos[nEndPos.length-1] = nFileLength; 2$qeNy
} pOIFO=k
} +;FF0_
"Q2[A]4E
6$fC R
//启动子线程 <adu^5BI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AGK+~EjL@
for(int i=0;i<nStartPos.length;i++) g@B9i=
{ C(e!cOG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P*I\FV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aOWbIS[8
nStartPos,nEndPos,i); ,dZ 9=]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <`-"K+e!J
fileSplitterFetch.start(); CEqfsKrsxE
} 1hi^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \&ERSk2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GlQ=M)E
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (t<i?>p
nEndPos = " + nFileLength); g>OGh o
// fileSplitterFetch[nPos.length-1].start(); k?|VFh1
ScZ$&n
f=}u;^
//等待子线程结束 ;u}MG3Y8
//int count = 0; oJyC{G
//是否结束while循环 X=${`n%LG
boolean breakWhile = false; c7wza/r>
P,I3E?! j
uZ<Bfrc
while(!bStop) ~g1@-)zYxK
{ Qbt fKn95
write_nPos(); |])%yRAGQ
Utility.sleep(500); m_\CK5T_
breakWhile = true; rUx%2O|qu
3Y=T8Gi#
OjrQ[`(E
for(int i=0;i<nStartPos.length;i++) Y<a/(`
{ ^6J*yV%
if(!fileSplitterFetch.bDownOver) =jg!@H=_i
{ Y*wbFL6`
breakWhile = false; i,;Q
break; .}Bb :*@
} -cY/M~
} 0A5xG&
if(breakWhile) "=4=Q\0PT
break; w$61+KHK
0vQkm<
"]zq<LmX
//count++; @OwU[\6fc}
//if(count>4) >6jyd{
// siteStop(); R`TM@aaS:
} _@?]!J[
w:z_EV!&
V!]e#QH;
System.err.println("文件下载结束！"); -J? df
} f4@Dn >BJ
catch(Exception e){e.printStackTrace ();} {a%T <WW
} BtU,1`El5
El"XF?OgpP
L d#
//获得文件长度 9&rn3hmP
public long getFileSize() b-~`A;pr
{ :4(7W[r6
int nFileLength = -1; e5veq!*C?
try{ prIq9U|@
URL url = new URL(siteInfoBean.getSSiteURL()); /91H!s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &^&k]JBaV
httpConnection.setRequestProperty("User-Agent","NetFox"); <@;eN&
jUBlIVl]
H26j]kY
int responseCode=httpConnection.getResponseCode(); x%cKTpDh!
if(responseCode>=400) %pTbJaM\U
{ 4I{|M,+
processErrorCode(responseCode); Eq'{uV:
return -2; //-2 represent access is error QD\S E
} RsTpjY*Xb
3 5|5|ma
)I!l:!Ij*D
String sHeader; 8MW|CM4Q
Nm\I_wjX
\%^<Ll
for(int i=1;;i++) g*Cs/w
{ 2Ybz`O!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,:=E+sS
//Utility.log(in.readLine()); "#[Y[t\Ia
sHeader=httpConnection.getHeaderFieldKey(i); =_ -@1 1a
if(sHeader!=null) 5%tIAbGW
{ nwO;>Qr
if(sHeader.equals("Content-Length")) ckhW?T>l
{ 7sHtJr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {wA@5+[
break; BT`/OD@
} < >f12pu
} {yspNyOx
else /\#qz.c2K
break; N;Hf7K
} %v}:#_va]
} .HGEddcC
catch(IOException e){e.printStackTrace ();} 0B3*\ H}5
catch(Exception e){e.printStackTrace ();} oX?2fu-
HnOp*FP
''f
Utility.log(nFileLength); ^f3F~XhY3
F Fg0}
=(Gv_
return nFileLength; `$MO.K{
} }\l5|Ft[!
`[o^w(l:5@
nX?fj<oR|
//保存下载信息（文件指针位置） z KJ6j]m
private void write_nPos() L & PhABZ
{ ih1SN,/
try{ q;B-np?U
output = new DataOutputStream(new FileOutputStream(tmpFile)); '1.T-.4>&
output.writeInt(nStartPos.length); {u9VHAXCf
for(int i=0;i<nStartPos.length;i++) V3I&0P k
{ O a-ZeCq
// output.writeLong(nPos); 9"MC<
output.writeLong(fileSplitterFetch.nStartPos); E;-R<X5n
output.writeLong(fileSplitterFetch.nEndPos); ^dqyX(
} p|AIz3
output.close(); S'TF7u
} A"S})
catch(IOException e){e.printStackTrace ();} 7CwG(c/5
catch(Exception e){e.printStackTrace ();} M[TgNWl/[
} ;Iv)J|*
7i6-Hq
UyK|KL
//读取保存的下载信息（文件指针位置） R<k4LHDy
private void read_nPos() Oo=}j
{ dc%+f
try{ Is?0q@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6ng . =
int nCount = input.readInt(); qIO)Z
nStartPos = new long[nCount]; fE_QB=9 cz
nEndPos = new long[nCount]; Kw-E%7gh4c
for(int i=0;i<nStartPos.length;i++) ^5"s3Qn
{ W@pVP4F0xM
nStartPos = input.readLong(); 2/>AmVM
nEndPos = input.readLong(); ,v)@&1Wh:
} .sjM$#V=
input.close(); {\lu; b!
} O`|'2x{[O
catch(IOException e){e.printStackTrace ();} ]S%qfna e1
catch(Exception e){e.printStackTrace ();} )v ['p
} =b !f
5:56l>0
#l:qht
private void processErrorCode(int nErrorCode) ]j_S2lt
{ hc~--[1c:
System.err.println("Error Code : " + nErrorCode); H#wn3O
} 9\Yj`,i5
}bix+/]
Pi)`[\{
//停止文件下载 \JN<"/
public void siteStop() yuKfhg7
{ R.>/%o
bStop = true; "C}nS=]8m
for(int i=0;i<nStartPos.length;i++) ::adT=
fileSplitterFetch.splitterStop(); 2eb :(D7Cq
{kW!|h&'
rj<%_d'Z`
} 0)9GkHVu(
} uX`Jc:1q3
//负责部分文件的抓取 Cw Z{&
**FileSplitterFetch.java ;:"~utL7
*/ ,:;nq>;
package NetFox; u4+)lvt
_!w# {5~
Ak>RLD25_
import java.io.*; ##R]$-<4dQ
import java.net.*; G^ n|9)CVW
"o[\Aec:
.;*0odxv
public class FileSplitterFetch extends Thread { i,* DWD+
#lV&U
m,)Re8W-
String sURL; //File URL #T !YFMh;
long nStartPos; //File Snippet Start Position |{ *ce<ip5
long nEndPos; //File Snippet End Position }$g5:k!
int nThreadID; //Thread's ID ?^,GaZ^V
boolean bDownOver = false; //Downing is over <}i\fJX6
boolean bStop = false; //Stop identical ng<|lsZd
FileAccessI fileAccessI = null; //File Access interface gEPCXf
uOm fpgO
KX`MX5?x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L`];i8=I
{ c5O1h8
this.sURL = sURL; NIV&)`w
this.nStartPos = nStart; 4my8 p Fk
this.nEndPos = nEnd; FC vR
nThreadID = id; H(n_g QAX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7J0PO}N
} s g6
KOwEw~
C7)].vUN
public void run() l^"gpO${K
{ Kd^ ._
while(nStartPos < nEndPos && !bStop) 9J l9\y9
{ (8H "'
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dR $@vDm
try{ {Ivu"<`L3
URL url = new URL(sURL); ~EX/IIa{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B4U+q|OD#
httpConnection.setRequestProperty("User-Agent","NetFox"); !aIIjWz]
String sProperty = "bytes="+nStartPos+"-"; 2BRY2EF
httpConnection.setRequestProperty("RANGE",sProperty); V{c n1Af
Utility.log(sProperty); eQzSWn[
X*d,z~k%*d
@0Tm>s
InputStream input = httpConnection.getInputStream(); [&)9|EV
//logResponseHead(httpConnection); bYowEzieF
RHE< QG
=Z%&jul
byte[] b = new byte[1024]; Pu}r` E_
int nRead; #!Kg?BR2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b"{7f
{ Uv5E$Y"e10
nStartPos += fileAccessI.write(b,0,nRead); !U=;e?o
//if(nThreadID == 1) Fvi<5v
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :c<C;.
} mezP"N=L~
qj=12;
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Utility.log("Thread " + nThreadID + " is over!"); H-0deJ[>
bDownOver = true; ]TD]
//nPos = fileAccessI.write (b,0,nRead); vW YN?"d
} wGb{O
catch(Exception e){e.printStackTrace ();} +F4xCz7f
} m!!uf/
} 2nOQ48haT
+| Cvv]Tx1
ioh_5 5e
//打印回应的头信息 )mp0k%
public void logResponseHead(HttpURLConnection con) VYlg+MlT0
{ &5C%5C~ch
for(int i=1;;i++) g[:5@fI#*
{ a Se.]_
String header=con.getHeaderFieldKey(i); l3(k
if(header!=null) /AW6XyMD_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); CDR^xo5 dP
Utility.log(header+" : "+con.getHeaderField(header)); #YjV3O5<
else [wIyW/+
break; >(d+E\!A
} vhKeW(z
} l ^$$d8
"T#c#?
ezHj?@
public void splitterStop() 7|"11^q
{ -XD\,y%zi
bStop = true; RI-whA8+
} o$Hc5W([Z
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v)rN]b]
} +h*&r~T
RC\TPG/8!
ib uA~\5
/* :i?Z1x1`
**FileAccess.java f)N67z6
*//文件访问(定位，写) @CWfhc-Ub
package NetFox; AE^&hH0^
import java.io.*; r\_aux^z
$F\&?B1.
GTJ\APrH
public class FileAccessI implements Serializable{ :=*>:*.Kb
6S]GSS<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Dt.OZ4w5
RandomAccessFile oSavedFile; `4Nc(aUr
long nPos; x"U/M?l
:tR%y"
SLZv`
public FileAccessI() throws IOException p|Z"< I7p(
{ m0/J3
this("",0); v }P~g
} UDuKG\_J<y
2ZLK`^S
:GGsQ n
public FileAccessI(String sName,long nPos) throws IOException C:gE
{ _%<7!|"
oSavedFile = new RandomAccessFile(sName,"rw"); |%6B#uy
this.nPos = nPos; `qs'={YtU
oSavedFile.seek(nPos); VwtGHF'
} 7+=j]+O
=>-b?F0(c
w)DO"Z7
public synchronized int write(byte[] b,int nStart,int nLen) "D@m/l
{ =U|J{^ >I
int n = -1; 1Kwl_jf
try{ 0!+ab'3a
oSavedFile.write(b,nStart,nLen); "@`M>)*o
n = nLen; Z(U&0GH`
} *7!}[ v_
catch(IOException e) P`U5kNN
{ tDIzn`$z
e.printStackTrace (); jY ^ndr0;
} B[b'OtH
P+"#xH
vs6`oW"{#
return n; B%'Np7
} t}*teo[
%!YsSk,
;O5NZa!.73
} G-,PsXSwe
73N%_8DH
;Oe6SNquT
/* U0)(k}Q)
**SiteInfoBean.java =PO/Q|-v?
*/ n7{1m$/
package NetFox; %tQIKjsVaY
lzm9ClkfH
9';0vrFeM
public class SiteInfoBean { 'OF)`5sj
/a9+R)Al
bM;tQ38*
private String sSiteURL; //Site's URL c}rRNS$F
private String sFilePath; //Saved File's Path I-;JDC?
private String sFileName; //Saved File's Name 94K;=5h
private int nSplitter; //Count of Splited Downloading File Of:e6N
!pDS*{)E
S:^Q(w7
public SiteInfoBean() [~jhOv^
{//nSplitter的缺省值为5 FIG5]u
//default value of nSplitter is 5 X}p4yR7'
this("","","",5); uP+ j_is
} ` qt4~rD
q:?g?v
oD"fRBS+$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J!yc9Q
{ '*)!&4f
sSiteURL= sURL; m=y6E, _
sFilePath = sPath; IXzad
sFileName = sName; iB]kn(2C
this.nSplitter = nSpiltter; [ >vS+G
{P = {)
.X:{s,@
} YW/<. 0rI
<GoE2a4Va
poXkH@[O
public String getSSiteURL() 75^-93
{ Dvx"4EA{7{
return sSiteURL; JaIj9KLNX
} Ylo@
t^h>~o'\
d628@~Ekn
public void setSSiteURL(String value) *[vf47)r!
{ tX)]ZuEi$
sSiteURL = value; ]%mg(&p4
} ]B5\S
)<3WVvB
A:p0p^*
public String getSFilePath() XP(q=Mw
{ N%Lh_2EzqV
return sFilePath; KNK0w5
} ;9prsvf
VvoJ85
5Impv3qaZ
public void setSFilePath(String value) [&Qrk8EN
{ Hq%`DWus\
sFilePath = value; HM76%9!
} jMw;`yh
(:hPT-1
4!monaB"e
public String getSFileName() M8g=t[\
{ *XNvb ^<
return sFileName; c<4pu
} J@R+t6$3O
SSH/q/
8:0l5cZE
public void setSFileName(String value) /}M@MbGMM
{ Rf8|-G-}#
sFileName = value; H5qa7JMZ
} _ -?)-L&g
IWMqmCbv
4}NFa;M1
public int getNSplitter() O^e !<bBd
{ Q2tGe~H
return nSplitter; V;)'FJ)]
} =-vk}O0C
"3\)@
'x!q*|zF2
public void setNSplitter(int nCount) y2<g96
{ b%v1]a[
nSplitter = nCount; Q2Q`g`*O:
} }>p)|YT"/
} 3g5i5 G\
qed; UyN
=Qz8"rt#
/* zlXkD~GV
**Utility.java 3z5,4ps
*/ /,B"H@J
package NetFox; 0dnm/'L
no;Yu
9|OQHy
public class Utility { S:oZ&
- +>~
T!/$@]%\7
public Utility() =fRP9`y
{ -`Z5#8P
xXHz)w
{N _v4})
} ,ciNoP*-~%
(-~tb-
//线程睡眠 |1t30_ /gS
public static void sleep(int nSecond) Nzr zLK
{ WM>9sJf
try{ d;'@4NX5+
Thread.sleep(nSecond); c| p eRO.
} ;GvyL>|-~
catch(Exception e) &#d;dcLe
{ (M[Kh ^
e.printStackTrace (); H]}- U8}sp
} h~F uuL
} l "d&Sgnj
VF6@;5p
//日志 P=S)V
public static void log(String sMsg) OBj.-jL
{ Oj<2_u
System.err.println(sMsg); Ujw^j
} \DfvNeF
Gz6FwU8L
){gOb
public static void log(int sMsg) (hmasy6hM
{ &5zUk++
System.err.println(sMsg); we{*%8I;
} YDDwvk H
} y0rT=kU
,ZH)[P)5P
Mu{mj4Y{
/* \yM[?/<
**TestMethod.java iRPd=)
*/ @++ X H}
package NetFox; SX*os$
_ sM$O>
*A8CJ
public class TestMethod { N8m^h:b
XrBLw}lD`N
(o e;pa
public TestMethod() <Oy%
{ ///xx/weblogic60b2_win.exe ~tz[=3!1H
try{ DhB:8/J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); drN^-e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }3N8EmS
SiteFileFetch fileFetch = new SiteFileFetch(bean); `uGX/yQ#=
fileFetch.start(); 7p2x}[ .\
} 9]hc{\
catch(Exception e){e.printStackTrace ();} #H5*]"w6I
3+!N[6Od9
'jmcS0f -
} dJCu`34Y'|
uOZ+9x(
lr^-
public static void main(String[] args) KnU"49
{ EmY8AN(*
new TestMethod(); jixU9]
} fzSZ>I0R
} I ][8[UZ
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