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)); 1tpt433
} *(*XNd||
for(int i=0;i<nEndPos.length-1;i++) .8|5;!`WB
{ '+S!>Lqb
nEndPos = nStartPos[i+1]; <@@@Pl!~
} +w@/$datI
nEndPos[nEndPos.length-1] = nFileLength; _8z
} ,(#n8|q4
} )7rMevF(xJ
*K=me/ 3
R*O6Z"h
//启动子线程 L=<,+m[!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uC`)?f*I
for(int i=0;i<nStartPos.length;i++) "r{ ^Y??
{ ,76nDXy`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D4GXZX8K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'BEM:1)
nStartPos,nEndPos,i); YjG:ECj}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T=cb:PD{%
fileSplitterFetch.start(); :OY7y`hRG
} Dw2$#d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &\r_g!Mh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Yg`z4U'6~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", iJu$&u
nEndPos = " + nFileLength); C1~Ro9si
// fileSplitterFetch[nPos.length-1].start(); ,rQPs
MWc{7,
GwlAEhP
//等待子线程结束 cFG%Ew@
//int count = 0; K~z9b4a>
//是否结束while循环 H*dQTy,
boolean breakWhile = false; }KrZ6cG9#
kI$X~s$r
MXpj_+@
while(!bStop) {D&:^f
{ K:sC6|wG
write_nPos(); 1FC1*7A[
Utility.sleep(500); 9hs7B!3pc>
breakWhile = true; !1?Nc}T0Q&
z#|tl/aP9
(KG>lTdN
for(int i=0;i<nStartPos.length;i++) `\S~;O
{ uwb>q"M
if(!fileSplitterFetch.bDownOver) u:4?$%rB
{ PR1%
breakWhile = false; o"A%dC_
break; nF|m*_DW
} P}Ule|&LK
} 5 %aT
if(breakWhile) R:DW>LB
break; [k6 5i
})r[qsv
"PPn^{bYm
//count++; ~ +z'pK~c
//if(count>4) I#hzU8Cc
// siteStop(); [5kaF"
} <?iwi[S
ag$UNV
lV!@h}mG
System.err.println("文件下载结束！"); $f<Rj/`&
} s"]LQM1|
catch(Exception e){e.printStackTrace ();} *gzX=*;x+?
} 7":0CU%%
Ib8xvzR6I&
7:T 5P
//获得文件长度 BI6o@d;=4
public long getFileSize() =Wk!mGc
{ u7<s_M3%N
int nFileLength = -1; A@"CrVE
try{ pfvNVu
URL url = new URL(siteInfoBean.getSSiteURL()); /F 1mYq~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dmD':1
httpConnection.setRequestProperty("User-Agent","NetFox"); wXsA-H/`
QFf lx
dPRGL hWF
int responseCode=httpConnection.getResponseCode(); 21U,!
if(responseCode>=400) 7uRXu>h
{ F/w!4,'<?5
processErrorCode(responseCode); .Su9fjy%
return -2; //-2 represent access is error GP/3r[MH
} N8l(m5Kk,k
';!02=-@
0$l D
String sHeader; /z+}xRS
vrIM!~*W
Hv1d4U"qM
for(int i=1;;i++) %k3a34P@
{ # 1,(I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a4! AvG
//Utility.log(in.readLine()); 4o2C=?@(
sHeader=httpConnection.getHeaderFieldKey(i); =jmn
if(sHeader!=null) ghiFI<)VY
{ wLC|mByq
if(sHeader.equals("Content-Length")) rT ~qoA\
{ x_\e&"x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @cF aYI
break; '?k*wEu
} B9^@]
} _dq.hW7
else *(x`cf;k
break; d&0^AvM@
} L+s,,k
} Os1(28rl
catch(IOException e){e.printStackTrace ();} /5_!Y>W
catch(Exception e){e.printStackTrace ();} p_QL{gn
\^3\_T&6
B;':Eaa@
Utility.log(nFileLength); }45&s9m=
([ xYOxcp5
Qp${/
return nFileLength; sEL[d2oO
} 'on, YEp
@&d/}Mx"t
OY6lt.t
//保存下载信息（文件指针位置） *Oo2rk nQ
private void write_nPos() cX553&
{ b07 MTDFH7
try{ i3>7R'q>
output = new DataOutputStream(new FileOutputStream(tmpFile)); qGgT<Rd~1
output.writeInt(nStartPos.length); Zcv1%hI
for(int i=0;i<nStartPos.length;i++) )fR'1_
{ o%!a
// output.writeLong(nPos); %Ow,.+m
output.writeLong(fileSplitterFetch.nStartPos); 1NT@}j~/
output.writeLong(fileSplitterFetch.nEndPos); x5 3aGi|
} <$HP"f+<S5
output.close(); /'p(X~X:l
} ?E2/ CM
catch(IOException e){e.printStackTrace ();} '8wA+N6Zr7
catch(Exception e){e.printStackTrace ();} #Gs] u
} 5"6Y=AuQ6
xq.,7#3
l>S~)FNwXJ
//读取保存的下载信息（文件指针位置） i%0Ml:Y
private void read_nPos() y#^d8 }+
{ kL,AY-Iu{@
try{ X%S?o
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pNI=HHx
int nCount = input.readInt(); pVPCxP
nStartPos = new long[nCount]; {cKKTDN
nEndPos = new long[nCount]; N/mTG2'<
for(int i=0;i<nStartPos.length;i++) Cjsy1gA
{ Fmk, "qs
nStartPos = input.readLong(); hIC$4lR~
nEndPos = input.readLong(); x2[A(O=
} FU~ Ip
input.close(); IiIF4 pQ,
} ~(%nnG6x
catch(IOException e){e.printStackTrace ();} aDTNr/I
catch(Exception e){e.printStackTrace ();} 3xh~xE
} {(AYs*5
'ac %]}`-
M"#xjP.
private void processErrorCode(int nErrorCode) 5R/!e`(m
{ k 0z2)3L
System.err.println("Error Code : " + nErrorCode); ">lu8F
} ;2-,Xzz8
'$PiyM|V
Qhsh{muw(
//停止文件下载 /A4zR
public void siteStop() 4E}/{1
{ tD.md_E
bStop = true; |28z4.
for(int i=0;i<nStartPos.length;i++) =h\,-8
fileSplitterFetch.splitterStop(); (5re'Pl
&hEtVkK
KE`}P<K&
} ]4yWcnf
} B{lBUv(B
//负责部分文件的抓取 'q8T*|/
**FileSplitterFetch.java uMtq4.
*/ `[w:l[i
package NetFox; A$Mmnu%
{xp/1?Mo*
vZmM=hW~
import java.io.*; iZB?5|*
import java.net.*; ogH{
*f=H#
1j "/}0fx
public class FileSplitterFetch extends Thread { @S yGj#
mTT1,|
gh|TlvnA
String sURL; //File URL 3G dWq*
long nStartPos; //File Snippet Start Position WrQe'ny
long nEndPos; //File Snippet End Position fa;\4#
int nThreadID; //Thread's ID t{| KL<d]
boolean bDownOver = false; //Downing is over (V)nHF*<>
boolean bStop = false; //Stop identical [84ss;.$
FileAccessI fileAccessI = null; //File Access interface MJd!J]E6
Q}2aBU.f
J1T_wA_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,8nu%zcVn
{ |?hNl2m
this.sURL = sURL; F$7>q'#
this.nStartPos = nStart; i<l_z&
this.nEndPos = nEnd; K2<"O qp_W
nThreadID = id; 7,ysixY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ) RS*MEgA
} Va"Q1 *"
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Pk!RgoWF
public void run() Tz[ck'k
{ [QEV6S]
while(nStartPos < nEndPos && !bStop) F~2bCy[Z
{ ) gbns'Z<
w5w,jD[
_8Cw_
try{ GuPxN}n 5
URL url = new URL(sURL); t<wjS|4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (-viP
httpConnection.setRequestProperty("User-Agent","NetFox"); X?&(i s
String sProperty = "bytes="+nStartPos+"-"; U1}-]^\
httpConnection.setRequestProperty("RANGE",sProperty); +Kw:z?
Utility.log(sProperty); }lt5!u~}
GKTt!MK
N"1o> !
InputStream input = httpConnection.getInputStream(); d(9ZopJrQ
//logResponseHead(httpConnection); @&#k['c
L_3Ao'SA
$L7Z_JD5
byte[] b = new byte[1024]; YEH /22
int nRead; p'{B|ujj6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) oJb${k<3
{ n@xC?D:t*
nStartPos += fileAccessI.write(b,0,nRead); Oo^kV:.)
//if(nThreadID == 1) jD1/`g%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;c p*]
} ^3"~ T
/k8Lu+OJ
Wu3or"lcw*
Utility.log("Thread " + nThreadID + " is over!"); g<pr(7jO
bDownOver = true; $p:RnH\H1
//nPos = fileAccessI.write (b,0,nRead); vy&'A$ H
} X5@+M!`
catch(Exception e){e.printStackTrace ();} |Hx#Uk#
} V>D8l @
} 4eH:eCZze
(7Su{tq
P/i{_r
//打印回应的头信息 hOZ:r =%
public void logResponseHead(HttpURLConnection con) >-U'mkIH
{ 3L}eFg,d
for(int i=1;;i++) 'KvSI=$
{ ac
String header=con.getHeaderFieldKey(i); kNq>{dNRx
if(header!=null) |H-%F?<{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Qw>~]d,Z
Utility.log(header+" : "+con.getHeaderField(header)); c12mT(+-
else NxY B)`~
break; >7g #e,d
} 'Ur1I"
} 6mp8v`b
#+CH0Z
sgYPR
public void splitterStop() gOiZ8K!
{ Uh[MBwK
bStop = true; `1Ui
} ;]v{3m
|5il5UP
7v'aw"~
} J9aqmQj('
U{1%ldOJ%
xB5qX7*.
/* p>#sR4d>
**FileAccess.java Q1kZ+b&
*//文件访问(定位，写) F8xz^UQO
package NetFox; ^mH:8_=(.
import java.io.*; To/6=$wto
2|`7_*\
aSse' C<a
public class FileAccessI implements Serializable{ 74_':,u;]~
}%75Wety
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z)%Ke~)<\@
RandomAccessFile oSavedFile; S\76`Ot
long nPos; u~rPqBT{d3
Q|KD$2rB
c,>y1%V*S{
public FileAccessI() throws IOException {L'uuG\9U
{ 3~q#P
this("",0); B*Z}=$1j
} osM[Xv
&=f] a
,FIG5-e,}
public FileAccessI(String sName,long nPos) throws IOException 'p_|Rw>
{ af@R\"N9c
oSavedFile = new RandomAccessFile(sName,"rw"); , wXixf2
this.nPos = nPos; E!A+J63zsw
oSavedFile.seek(nPos); B,V:Qs6"
} pk8`suZ
hZIbN9)8A
L;\f^v(
public synchronized int write(byte[] b,int nStart,int nLen) ]ZR}Pm/CA
{ v[~~q
int n = -1; U8S<wf&
try{ t $m:
oSavedFile.write(b,nStart,nLen); `}:pUf
n = nLen; "tT68
} cqYMzS t
catch(IOException e) P(oGNKAS
{ 4V<.:.k
e.printStackTrace (); 9y'To JZ6
} _|r/*(hh
Y sDai<
%y)]Q|
return n; sWyx_
} F4NMq&_
'QSj-
7Y?59 [
} _U|rTil
Ddh
xLdkeuL[%
/* %MCJ%Ph
**SiteInfoBean.java &8;Fi2}(L
*/ /z m+
package NetFox; g-pEt#
h e=A%s
[jz@d\k$_
public class SiteInfoBean { HQZJK82
wZ5k|5KtW
P^aNAa
private String sSiteURL; //Site's URL j];#=+
private String sFilePath; //Saved File's Path EG8%X"p
private String sFileName; //Saved File's Name ZU$QwI8
private int nSplitter; //Count of Splited Downloading File ep6V2R
18^K!:Of
wG&Z7C b
public SiteInfoBean() |w"G4J6ha
{//nSplitter的缺省值为5 =}"P;4:
//default value of nSplitter is 5 a8YFH$Xh
this("","","",5); !a4`SjOgu
} ')T*cLQ><
]`q]\EH
%!7A" >ai
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^S`N\X
{ mg< v9#
sSiteURL= sURL; d};[^q6X
sFilePath = sPath; ov5g`uud
sFileName = sName; )gx*;z@
this.nSplitter = nSpiltter; t*`G@Nj
)EK\3q
Sc ijf 9
} %CZGV7JdA
IL,iu
33ZHrZ
public String getSSiteURL() Jt:)(&-t
{ _VB;fH$
return sSiteURL; 4j}.=u*X7
} @X2zIFm
?AVnv(_
bN&DotG
public void setSSiteURL(String value) :*vSC:q
{ _}gfec4o
sSiteURL = value; [x%8l,O #l
} eNK6=D|
y(*5qa<>
{`Z=LLL
public String getSFilePath() HqI[]T@
{ `46|VQAx
return sFilePath; S\ K[l/
} z%]3`_I
M96Nt&P`
qYPgn_
public void setSFilePath(String value) L'$({
{ Zbr1e5?
sFilePath = value; =Qn8Y`U
} iOk`_LG#
i!G<sfL
hXD`OlX
public String getSFileName() xouBBb=
{ b)>l7nOc
return sFileName; tR.>d
} "u'dd3!
-M+o;
)+"(7U<
public void setSFileName(String value) 1]W8A.ZS
{ g2vt(Gf;
sFileName = value; *l@T 9L[M'
} @.=2*e.z|b
VrKLEN\
djn<Oc`
public int getNSplitter() t Kjk<
{ uG/bCb+V
return nSplitter; KkJE-k*D+w
} ug/P>0
Ko!a`I2M}
]E*xn
public void setNSplitter(int nCount) 6J965eM'[
{ cef:>>6_
nSplitter = nCount; <899r \
} X;{U?`b-
} ;T<'GP'/r
mp0s>R
SwO8d;e
/* J=H8^4M
**Utility.java ()fYhk|W
*/ ?QcS$i
package NetFox; IFXnGDG$
'h>l_A
>p3S,2SM
public class Utility { pW&8 =Ew
cr!sq.)s
m;<5QK8f
public Utility() ZV!*ZpTe~
{ 9x14I2
s{fL~}Yz
ai)?RF
} lC^?Jk[N
`J}FSUn\
//线程睡眠 ` kZ"5}li
public static void sleep(int nSecond) d 8z9_C-
{ L @8[.
try{ c-[IgX e
Thread.sleep(nSecond); UFE~6"t(
} ?osYs<k \
catch(Exception e) 'fIG$tr9X
{ =/N0^
e.printStackTrace (); ?o(Y\YJf
} I -XkxDw
} ,`(Qs7)Xx
zENo2#{_N
//日志 /j:-GJb*!u
public static void log(String sMsg) ]r1Lr{7^S
{ Y2>*' nU
System.err.println(sMsg); k")3R}mX
} )1&,khd/u
SU4~x0
z\<gm$1CB
public static void log(int sMsg) $t>ow~Xi
{ rzKn5Z
System.err.println(sMsg); a@-!,Hi
} e pAC%a
} =l$qwcfbo
lW@i,1
zh4m`}p
/* t<qXXQ&5
**TestMethod.java CHM+@lD
*/ iu'rc/=V
package NetFox; 3]/Y=A
`{\10j*B
SA6.g2pFz
public class TestMethod { j"<F?k@`Q
[u8JqX
V[">SiOg
public TestMethod() LMYO>]dg
{ ///xx/weblogic60b2_win.exe -GL-&^3IjH
try{ f>+:UGmP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oz?6$oE(bt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M+\LH
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5?MKx!%
fileFetch.start(); !%YV0O0
} S]DYEL$
catch(Exception e){e.printStackTrace ();} "cX*GTNi8
V, e
5,?Au
} j=w`%nh4"f
qo0]7m7|
QLyBP!X-
public static void main(String[] args) PF-"^2&_
{ 2ZFp(e^%
new TestMethod(); Fy]j33E
} +DP{_x)t
} f<( ysl1[
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