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)); gVb;sk^
} P#iBwmwN+.
for(int i=0;i<nEndPos.length-1;i++) yAaMYF@
{ U1I2+;"#A
nEndPos = nStartPos[i+1]; mzDbw-#
} @<h@d_8^k
nEndPos[nEndPos.length-1] = nFileLength; H>2)R7h
} \\6/"
} PKmr5FB
Y\s@'UoVN
<&B)i\j8=b
//启动子线程 G/b $cO}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Uh{|@D
for(int i=0;i<nStartPos.length;i++) @?TOg{:
{ {ymD.vf=9+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K;Fy&p^d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rxt)l
nStartPos,nEndPos,i); ?nE<Aig
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G{)2f&<
fileSplitterFetch.start(); l1nrJm8
} :W^ k3/t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9[T}cN=|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ww:,O48%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ean #>h
nEndPos = " + nFileLength); ht)J#Di
// fileSplitterFetch[nPos.length-1].start(); ',~,hJ0
n{aD4&
NsPt1_Y8
//等待子线程结束 Zh,(/-XN;
//int count = 0; ]%pr1Ey
//是否结束while循环 8a)lrIg
boolean breakWhile = false; mSr(PIH{\
PCtf&U
"5,'K~hz
while(!bStop) ^Yul|0*J
{ zr2oU '+
write_nPos(); yCpU173V
Utility.sleep(500); wX[g\,?}'
breakWhile = true; IBZ_xU\2
,:;ZzHzR0
?`8jn$W^
for(int i=0;i<nStartPos.length;i++) f<?v.5($
{ MDAJ p>o
if(!fileSplitterFetch.bDownOver) ;Lr]w8d
{ "dQ02y
breakWhile = false; m5`<XwD9
break; v;1<K@UT
} 5Sl vCL
} BS!VAHO"V
if(breakWhile) \xR1|M
break; b*(74>XY
E+)3n[G
n 'gU
//count++; ir!/{IQx
//if(count>4) p?PK8GL
// siteStop(); vnc-W3N
} b1\.hi
c&X2k\
mQUI9
System.err.println("文件下载结束！"); Xs}.7
} grrM[Y7#~b
catch(Exception e){e.printStackTrace ();} UU'0WIbY6
} a]\l:r
4h~CDy%_
ip8%9fG\>
//获得文件长度 fRh}n ^X
public long getFileSize() ZD~ra7
{ {9B"'65o
int nFileLength = -1; :8=7)cW
try{ gjFpM.D-.
URL url = new URL(siteInfoBean.getSSiteURL()); 0i[v,eS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y!eT>4Oyg
httpConnection.setRequestProperty("User-Agent","NetFox"); ;8m)a
"lLwgh;
H< 51dJn~
int responseCode=httpConnection.getResponseCode(); ^pwT8Bp
if(responseCode>=400) 2fN2!OT
{ P8[rp
processErrorCode(responseCode); Sq:,6bcG
return -2; //-2 represent access is error *be"$Q
} Opavno%&
?`hA:X<
M47t(9krV
String sHeader; Zo`_vx/{j
]sLdz^E3D
[8jIu&tJf
for(int i=1;;i++) w#}[=jy
{ uo`zAKM&A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "rA-u)Te
//Utility.log(in.readLine()); '9u(9S
sHeader=httpConnection.getHeaderFieldKey(i); fQQj2>3w
if(sHeader!=null) ;-kC&GZf
{ R`KlG/Tk
if(sHeader.equals("Content-Length")) FdGnNDl*e
{ ?mwa6]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y#[xX2z9
break; D,\hRQ
} cXw8#M!
} Lo,uH`qU
else {^":^N)
break; {'cm;V+
} >)^Q p-
} cS#yfN,
catch(IOException e){e.printStackTrace ();} &ea6YQ
catch(Exception e){e.printStackTrace ();} L;h|Sk]{
fDjJdRS"
=gC% =
Utility.log(nFileLength); BCO (,k
h.\p+Qw.
a4XK.[O
return nFileLength; MoXai0d%
} jX.'G
YZAQt*x
<qVOd.9c
//保存下载信息（文件指针位置） b/_u\R ]-'
private void write_nPos() 7)RRCsn
{ Z+=WICI/2
try{ >,.\`.0
output = new DataOutputStream(new FileOutputStream(tmpFile)); '|}H,I{
output.writeInt(nStartPos.length); 5&.I9}[)j
for(int i=0;i<nStartPos.length;i++) I+QM":2
{ #r,!-;^'p
// output.writeLong(nPos); cd`P'GDF
output.writeLong(fileSplitterFetch.nStartPos); g'Wr+(A_
output.writeLong(fileSplitterFetch.nEndPos); Z5g*'
} U] P{~
output.close(); <kJ`qbOU
} |9Y~k,rF
catch(IOException e){e.printStackTrace ();} y7,t"XV
catch(Exception e){e.printStackTrace ();} L#WGOl
} ^A=2#j~H\
:)y3&I
#7"";"{z|
//读取保存的下载信息（文件指针位置） J\FLIw4
private void read_nPos() oBs5xH7@-
{ G^Y^)pc]
try{ )LsUO#%DO
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *to#ZMR;!
int nCount = input.readInt(); i*8j|
nStartPos = new long[nCount]; l3+G]C&<
nEndPos = new long[nCount]; 3sgo5D-rMI
for(int i=0;i<nStartPos.length;i++) /z(d!0_q|v
{ Jpy~5kS
nStartPos = input.readLong(); pq%inSY
nEndPos = input.readLong(); ol~ tfS
} ~i.rk#{?D
input.close(); KpIY>k
} ,."wxP2u
catch(IOException e){e.printStackTrace ();} RU~Pa+H
catch(Exception e){e.printStackTrace ();} TEbIU8{Y
} i6S["\h>
YV'B*arIA
Esm=sPW
private void processErrorCode(int nErrorCode) %0({MU
{ q,OCA\
System.err.println("Error Code : " + nErrorCode); *,)1Dcv(
} {{)pb>E
M,cz7,
IR?nH`V
//停止文件下载 >QPCYo<E
public void siteStop() ]bbP_n8
{ 3NdO3-~)
bStop = true; $oJjgAxcZ
for(int i=0;i<nStartPos.length;i++) #bCUI*N"P
fileSplitterFetch.splitterStop(); =@&>r5W1
s@g _F
p}JGx^X~
} o?+?@Xb'
} rHqP[[4B'
//负责部分文件的抓取 a@AIv"q
**FileSplitterFetch.java RjR+'<7E^
*/ E>:#{%
package NetFox; 'e6J&X
4sfq,shRq
cEn|Q
import java.io.*; 8Q0/kG
import java.net.*; +:Nz_l
|,({$TrF
Y\ ;hjxR-
public class FileSplitterFetch extends Thread { sLzZ}u?(
7\X_%SM%
ulk/I-y
String sURL; //File URL s){VU2.ra
long nStartPos; //File Snippet Start Position 'H"!%y{:i
long nEndPos; //File Snippet End Position ?m9=Me
int nThreadID; //Thread's ID ,|]k4F
boolean bDownOver = false; //Downing is over I,"q:QS+
boolean bStop = false; //Stop identical ]VEc9?
FileAccessI fileAccessI = null; //File Access interface 4q?R3\e;
?kRx;S+
tOZ-]>U
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException P)~olrf
{ sn Ou
this.sURL = sURL; LMN`<R(q]
this.nStartPos = nStart; b?<@
this.nEndPos = nEnd; f3s4aARP
nThreadID = id; jaIcIc=Pf
fileAccessI = new FileAccessI(sName,nStartPos);//定位 aCi)icn$
} mR|']^!SE
Y1F%-o
XsSDz}dg
public void run() fo<nk|i
{ TkIiO>
while(nStartPos < nEndPos && !bStop) ks,d4b=->
{ h\5~&}Hp
m63>P4h?
hpq\
try{ Bsk` e
URL url = new URL(sURL); h A'>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oW>e.}d!
httpConnection.setRequestProperty("User-Agent","NetFox"); PG@C5Rnu
String sProperty = "bytes="+nStartPos+"-"; ZTj!ti;5
httpConnection.setRequestProperty("RANGE",sProperty); Ef3="}AI;
Utility.log(sProperty); e@5w?QzW
O7od2fV(i7
#iRd2Qj%
InputStream input = httpConnection.getInputStream(); FTzc,6
//logResponseHead(httpConnection); uTdz$Nh
F^lau f
{IF$\{Al
byte[] b = new byte[1024]; QHsJo|.
int nRead; #miG"2ea..
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <p?oFD_e4
{ 8|u8J0^
nStartPos += fileAccessI.write(b,0,nRead); jN(c`Gb
//if(nThreadID == 1) Tt_QAIl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,>nf/c0.
} !<F5W<V
.3>q3sS
e:.D^GFi
Utility.log("Thread " + nThreadID + " is over!"); WopA7J,
bDownOver = true; Q91mCP~$
//nPos = fileAccessI.write (b,0,nRead); IU"n`HS
} f1B t6|W%
catch(Exception e){e.printStackTrace ();} %fXgV\xY
} NFG~PZ`6R
} YpG6p0 nd
67||wh.BU
umpa!q};
//打印回应的头信息 E{\T?dk1$
public void logResponseHead(HttpURLConnection con) DweF8c
{ UnyJD%a
for(int i=1;;i++) zs'Jgm.v
{ H1 i+j;RN
String header=con.getHeaderFieldKey(i); Y~I0\8s-
if(header!=null) f%P#.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); w;kiH+&
Utility.log(header+" : "+con.getHeaderField(header)); >#`{(^
else z)R\WFBW
break; XAB/S8e
} 7{VN27Fa_
} _Om5wp=:
R-2Abyts2
d7Z$/ $
public void splitterStop() I]Z"?T
{ UI wTf2B
bStop = true; /<J5?H
} (m')dSZ
7p{2&YhB
KPZqPtb;
} ,8DjQz0ZPo
"ER=c3 t
J6nH|s8
/* ~!e(e2
**FileAccess.java ApcE)mjpc
*//文件访问(定位，写) ^~3{n
package NetFox; !F2JT@6
import java.io.*; kPSi6ci
y#nyH0U
!1<>][F
public class FileAccessI implements Serializable{ o KY0e&5
JaN53,&<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7+$P6[*
RandomAccessFile oSavedFile; n]K{-C;
long nPos; #* 8^ar<
kcP&''
Gd|jE
public FileAccessI() throws IOException ZCDXy
{ cejD(!MKe
this("",0); JNI&]3[C>?
} xfqU atC
zB6&),[,v
9"dZ4{\!
public FileAccessI(String sName,long nPos) throws IOException %D ,(S-Uj
{ ?~;q r
oSavedFile = new RandomAccessFile(sName,"rw"); kP&Ekjt@
this.nPos = nPos; Ft@ZK!'@
oSavedFile.seek(nPos); yq` ,)
} *[b~2
\obM}caT
4@@gC&:Y
public synchronized int write(byte[] b,int nStart,int nLen) FCChB7c`
{ f%%'M.is
int n = -1; D)eRk0iC
try{ # tU@\H5kN
oSavedFile.write(b,nStart,nLen); De49!{\a
n = nLen; FuP~_ E~
} = Fwzm^}6
catch(IOException e) g7K<"Z {M
{ Jx8DVjy
e.printStackTrace (); Z}>+!Z
} V|;os
D ~NWP%H
ASr3P5/
return n; x' 3kHw
} _2xYDi
^E3 HY@j
QhPpo#^
} :Lq=)'d;6
w)}@svv"
V&d?4i4/Q
/* =CL h<&
**SiteInfoBean.java #3-hE
*/ C+-sf
package NetFox; q94*2@KV
Kxsj_^&|i
J 77*Ue^
public class SiteInfoBean { Bh6lK}9
v3]~*\!5
)umW-A
private String sSiteURL; //Site's URL }ct*<zj[~u
private String sFilePath; //Saved File's Path XKbTjR
private String sFileName; //Saved File's Name S@C"tHD
private int nSplitter; //Count of Splited Downloading File zi,":KDz#
qjIcRue'"
TA+/35^?
public SiteInfoBean() <}AmzeHr+
{//nSplitter的缺省值为5 'V*8'?
//default value of nSplitter is 5 ~tqNxlA
this("","","",5); Xgo`XsA
} }Q{4G
C,5Erb/
4cAx9bqA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) jq+:&8!8(e
{ pEiq;2{~Yn
sSiteURL= sURL; +fq;o8q
sFilePath = sPath; Y67i\U>?
sFileName = sName; jHc/ EZB
this.nSplitter = nSpiltter; [.4D<}e
#M8>)oc
Jl89}Sf
} &3Mps[u:h
&sS]h|2Z5
Y\{lQMCy
public String getSSiteURL() suZ`
{ /S%!{;:
return sSiteURL; |r53>,oR<:
} 5$ rV0X,O
E=~Ahkg
W7 9.,#
public void setSSiteURL(String value) t($z+C<
{ 6bt{j
sSiteURL = value; i<{/r-w=E
} Z/I`XPmk
R]_fe4Y0
hFt~7R
public String getSFilePath() QK`2^
{ "4i_}
return sFilePath; (OHd}YQ
} n`7n5M*
,NQ>,}a0
Mer\W6e"e
public void setSFilePath(String value) pPZ^T5-ks
{ 0mR
sFilePath = value; 2)>Ty4*
} |-VbJd
*wJ'Z4_5F
ij1g2^],4
public String getSFileName() |}K7Q
{ `H\NJ,
return sFileName; \fD[Ej
} ~7&O[
y1hJVYE2
.(zZTyZr
public void setSFileName(String value) 7)au#K6
{ Cl3hpqv1I
sFileName = value; c)=UX_S!
} [KwwhI@3
QjwCY=PK!
Q@#Gm9m
public int getNSplitter() G3t 4$3|
{ 0B~Q.tyP
return nSplitter; .Dg'MMBM
} x$tzq+N
g].hL
=;A~$[g
public void setNSplitter(int nCount) ~b{j`T
{ u+uu?.bM
nSplitter = nCount; auQfWO[ u
} .[#bOp*
} &M^FA=J\
f*~z|
dCM*4B<
/* F`YxH*tO7
**Utility.java 4WV)&50
*/ ) XHcrm&
package NetFox; _i{4 4zE
VR0#"
quw:4W>
public class Utility { -2Azpeh
\78kShx
T?E[LzZg
public Utility() y7#4Mcc`~
{ a'ODm6#
XG}pp`{o
6WnGP>tc.
} H@WQO]PA
}D eW2Jp
//线程睡眠 j>OB<4?.+
public static void sleep(int nSecond) /I&b5Vp
{ 8?7:sfc
try{ iP~dH/B|v
Thread.sleep(nSecond); 15FGlO<<
} C\dlQQ
catch(Exception e) %S<( z5
{ DY%#E9
e.printStackTrace (); k|}S K9
} "A?_)=zZ
} '%"#]
p,w6D,h
//日志 Ey"<hAF
public static void log(String sMsg) ^~dvA)bH
{ +(<}`!9M*
System.err.println(sMsg); ~X -.@k'
} v+Q#O[
(_lc< Bj
'u2Qq"d+
public static void log(int sMsg) Sm%MoFf
{ +iPS=?S
System.err.println(sMsg); ~ Qt$)
} ~:srm#IX
} 8Cr?0Z
=JnUTc_u
TGz5t$]I
/* S&P5##.u`
**TestMethod.java b#C"rTw
*/ N7xkkAS{
package NetFox; %j=,c{`Q
lA<IcW
IczEddt@'
public class TestMethod { rkl/5z??
w`Dzk.2
&7X0 ;<
public TestMethod() ca_8S8lv
{ ///xx/weblogic60b2_win.exe jL)aU> kN
try{ }r/L 9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `#X{.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -K/' }I
SiteFileFetch fileFetch = new SiteFileFetch(bean); F77[fp
fileFetch.start(); >}/"gx
} xTM&SVNbL_
catch(Exception e){e.printStackTrace ();} }h>e=<
p$@=N6)I.k
<96ih$5D1
} q#PGcCtu
nx,67u/Pb
k>n^QHM
public static void main(String[] args) zT~ GBC-IX
{ DD'<zL[
new TestMethod(); VPg`vI$(X
} vVLR9"rHM
} j>R7OGg'
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