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)); ^<R*7mB*
} !+4}x;!8
for(int i=0;i<nEndPos.length-1;i++) y8Bi5Ae,+1
{ \$2E
nEndPos = nStartPos[i+1]; Kv[,!P"Y
} gg(^:`+
nEndPos[nEndPos.length-1] = nFileLength; *BYSfcX6
} /s>ZT8vaAs
} Eoug/we
;K[`o/#4"
MX 2UYZ&
//启动子线程 'Lft\.C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; EnJAHgRV;e
for(int i=0;i<nStartPos.length;i++) jZcjiOX
{ g_}r)CgG|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `Njv#K} U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !Jw
nStartPos,nEndPos,i); Yz0ruhEMk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !Re/W ykY
fileSplitterFetch.start(); ,>n 4 `A
} N0h"EV[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q#-szZQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \.A~>=:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R/M:~h~F!
nEndPos = " + nFileLength); ur-&- G^
// fileSplitterFetch[nPos.length-1].start(); BlS0I%SN
@4m_\]Wy
AA9OElCa
//等待子线程结束 :2?J#/o
//int count = 0; gOZ$rv^g
//是否结束while循环 }'dnL
boolean breakWhile = false; }> k9]Y
9}Tf9>qP>M
W$@q ~/E
while(!bStop) [1'`KJ]
{ 4^VY
write_nPos(); C_?L$3 U0
Utility.sleep(500); *plsZ*Q8
breakWhile = true; lNQt
N\Bygjw|
3=1aMQ
for(int i=0;i<nStartPos.length;i++) ;uNcrv0J
{ mCe,(/>l+
if(!fileSplitterFetch.bDownOver) M ]W'>g)G
{ K IiVz<
breakWhile = false; b5 YE4h8%
break; )+Wx!c,mb
} FGBPhH% (8
} }%[TJ@R;
if(breakWhile) y@'8vOh`
break; {IJV(%E
3x9O<H}
V< 0gD?Kx
//count++; [a\:K2*'
//if(count>4) @#1k+tSA,
// siteStop(); )H#Hs<)Qy
} ErJi
db:b%1hk:
1agyT
System.err.println("文件下载结束！"); eb2~$ ,$
} *@lNL=%R
catch(Exception e){e.printStackTrace ();} m,$oV?y>j
} Ck2O?Ne
gpsEN(.w
too=+'<N</
//获得文件长度 RyC]4QyC
public long getFileSize() BV$lMLD{r
{ gQgG_&xkC
int nFileLength = -1; PkQuN;a
try{ 9zEO$<e o
URL url = new URL(siteInfoBean.getSSiteURL()); ~qLbyzHaB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I)V2cOrXM
httpConnection.setRequestProperty("User-Agent","NetFox"); Vp\BNq_!s
=U!'v X d
CN\SxK`,
int responseCode=httpConnection.getResponseCode(); j/{F#auI
if(responseCode>=400) {LbNKjn
{ eHi|_3A&*
processErrorCode(responseCode); mKtZ@r)u
return -2; //-2 represent access is error (tP>z+
} *j2P#et
EYd`qk3
+?[TH?2c+
String sHeader; xaX3<V@S
QS,IM>Nr
\CM(
for(int i=1;;i++) 7qV_QZ!.
{ bqN({p&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y'xB? >|
//Utility.log(in.readLine()); 7w_`<b6
sHeader=httpConnection.getHeaderFieldKey(i); ej47'#EY
if(sHeader!=null) +,9I3Dq
{ xvQJTRk
if(sHeader.equals("Content-Length")) c~b[_J)
{ !v<r=u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,(}7 ST
break; abuHu'73
} bKYLBu:
} [Oe$E5qv)]
else FEw51a+V
break; 5Jd&3pO
} FAJ\9
} !]&a/$U
catch(IOException e){e.printStackTrace ();} aJ88U69
catch(Exception e){e.printStackTrace ();} 69ia #
U_m<W$"HF
m.EI("n"J
Utility.log(nFileLength); !m^;Apuy
s\1h=V)!H
pvQw+jX
return nFileLength; u1/4WYJeJ
} :h=];^/E
a9mLPP
I1BVqIt1i
//保存下载信息（文件指针位置） v$s3f|Y
private void write_nPos() `QXO+'j4
{ )t9<cJ=
try{ 2PE|4zG
output = new DataOutputStream(new FileOutputStream(tmpFile)); HvN!_}[
output.writeInt(nStartPos.length); _-x|g~pV*
for(int i=0;i<nStartPos.length;i++) di>"\On-
{ 2B3H-`
// output.writeLong(nPos); YH&`+ +
output.writeLong(fileSplitterFetch.nStartPos); f%` =>l
output.writeLong(fileSplitterFetch.nEndPos); b/5?)!I
} SN(:\|f 2
output.close(); kq8:h
} {'E%SIRZ)
catch(IOException e){e.printStackTrace ();} 1T!b#x4
catch(Exception e){e.printStackTrace ();} "n,">
} xmb]L:4F
IkFrzw p
v*<hE>J0
//读取保存的下载信息（文件指针位置） jxL}tS{j
private void read_nPos() "yXKu)_
{ lPSyFb"
try{ Zk__CgS#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /T]2ZX>
int nCount = input.readInt(); H ifKa/}P8
nStartPos = new long[nCount]; /@X!
nEndPos = new long[nCount]; U2
for(int i=0;i<nStartPos.length;i++) T=(/n=
{ t,M_
nStartPos = input.readLong(); VUxuX5B3M
nEndPos = input.readLong(); ZZ?0%9
} E?z3 D*U
input.close(); __teh>MC
} ^Wo/vm*]
catch(IOException e){e.printStackTrace ();} <iuESeDG
catch(Exception e){e.printStackTrace ();} )o;/*h%@
} iagl^(s
a$yAF4HR<
aTuD|s
private void processErrorCode(int nErrorCode) e) 42SL^s
{ f5"1WtB
System.err.println("Error Code : " + nErrorCode); u\ro9l
} G|Rsj{2'
7"@^JxYN
^[,Q2MHCT(
//停止文件下载 d&4ve Lu
public void siteStop() M(KsLu1
{ ExeD3Zj
bStop = true; =,$*-<p=3
for(int i=0;i<nStartPos.length;i++) R8I%Cyc
fileSplitterFetch.splitterStop(); f_Ma~'3
dKTyh:_{
3p6QJuSB
} Oq@+/UWX
} f6vhW66:?x
//负责部分文件的抓取 njtz,qt_;G
**FileSplitterFetch.java 2-728
*/ ukpbx;O:hc
package NetFox; {^=T&aCYdS
"s]r"(MX
aUa.!,_dh
import java.io.*; a$r- U_?
import java.net.*; $nF|n+m
.A<G$ db ?
/2l&D~d"
public class FileSplitterFetch extends Thread { Z8E-(@`q5Q
EudX^L5U<d
Yz]c'M@
String sURL; //File URL r*HbglB
long nStartPos; //File Snippet Start Position #%N v\g;
long nEndPos; //File Snippet End Position M<^]Ywq*p
int nThreadID; //Thread's ID 7aRtw:PQn
boolean bDownOver = false; //Downing is over fqrQ1{%UH
boolean bStop = false; //Stop identical V 6I77z
FileAccessI fileAccessI = null; //File Access interface `|coA2$rw
$9+|_[ ]v.
FlGU1%]m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException J!Er%QUR
{ :dq.@:+<R
this.sURL = sURL; 94VtGg=b}
this.nStartPos = nStart; J{;XNf =
this.nEndPos = nEnd; KBE3q)
nThreadID = id; .2"-N5Z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m:B9~lbT+
} E@ J/_l;
M2H +1ic
(StX1g'
public void run() 60,z!Vv
{ T<yAfnTb`
while(nStartPos < nEndPos && !bStop) X-LCIT|1
{ /By:S/[1pL
|y9(qcKn$
v+Eub;m
try{ 0DtewN{Z
URL url = new URL(sURL); 2[~|#0x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ak3cE_*Y/
httpConnection.setRequestProperty("User-Agent","NetFox"); %O6r
String sProperty = "bytes="+nStartPos+"-"; !q\MXS($#u
httpConnection.setRequestProperty("RANGE",sProperty); ]QKo>7%[
Utility.log(sProperty); p3r("\Za,
GsIVx!
>[}lC7 z,
InputStream input = httpConnection.getInputStream(); R !g'zS'
//logResponseHead(httpConnection); GWFF.Mo^
yq.<,b=87
f~Y;ZvB
byte[] b = new byte[1024]; F<.oTP-B
int nRead; ezimQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !Gob `# r
{ <*JFY%y"
nStartPos += fileAccessI.write(b,0,nRead); qm^|7m^
//if(nThreadID == 1) "5<:Dj/W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ( jACLo
} GuK3EM*_
P5Lb)9_Jw
L~oy|K67
Utility.log("Thread " + nThreadID + " is over!"); "<Ozoo1&w
bDownOver = true; L4O.=*P1
//nPos = fileAccessI.write (b,0,nRead); r{>Q{$Q
} UE9RrfdN
catch(Exception e){e.printStackTrace ();} W(pq_H'
} :eIi^K z[
} Z8C~o)n9
l266ufO.u-
}1fi#
//打印回应的头信息 Cj%n?-
public void logResponseHead(HttpURLConnection con) ;w/@_!~
{ >?<S(
for(int i=1;;i++) Tp46K\}Uf
{ T@wgWE<0y_
String header=con.getHeaderFieldKey(i); 5{/uHscwLa
if(header!=null) 'oKen!?A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); u9nJ;:
Utility.log(header+" : "+con.getHeaderField(header)); |I[/Fl:
else "; 1@f"kw
break; P~ : N
} d1P|v( `S9
} "QD>m7
"I3 #/~q
8Y4mTW
public void splitterStop() IR2=dQS
{ dx@|M{jz'
bStop = true; Mj&G5R~_
} s$%t2UaV
Vv54;Js9
`j1oxJm
} azz=,^U#
\sMe2OL#z
*\.8*6*$!
/* rJZR8bo
**FileAccess.java lArKfs/
*//文件访问(定位，写) +7\d78U
package NetFox; '-U&S
import java.io.*; ]p8zT|bv
p}oGhO&=
/4*Y#IpZ
public class FileAccessI implements Serializable{ 2FR+Z3&z
!4-4i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X+1Mv
RandomAccessFile oSavedFile; d-3.7nJ:
long nPos; /#WvC;B
V7b;qC'
]_BH"ng}
public FileAccessI() throws IOException Q,K$)bM
{ ({ O~O5k
this("",0); %pIP#y[4
} {E; bT|3z
.TMLg(2hgv
}* \*<d 3
public FileAccessI(String sName,long nPos) throws IOException ,ZghV1z
{ [ *Dj7zt:
oSavedFile = new RandomAccessFile(sName,"rw"); y8_$YA/g
this.nPos = nPos; b)@D@K"5
oSavedFile.seek(nPos); ?3lAogB
} ph}%Ay$
2x>7>;>
a^={X<K|/
public synchronized int write(byte[] b,int nStart,int nLen) MyZVx|7E
{ ZIKSHC9
int n = -1; ,Nt^$2DZW
try{ t~7OtPF
oSavedFile.write(b,nStart,nLen); ]1FLG*sB
n = nLen; TjDtNE
} 'hE'h?-7
catch(IOException e) cZJ5L>ox
{ Y[l<fbh(}
e.printStackTrace (); ^,0Lr$+
} lb$_$+@Vr
eTFep^[
pdB\D
return n; CT5s`v!s
} N>Ih2>8t
W]oa7VAq
76bMy4re
} hxzA1s%~
CuD}Uo+u
m.p$f$A_
/* C6EGM/m8
**SiteInfoBean.java C{,^4Eh3r
*/ 9dw* ++
package NetFox; XUzOt_L5<
p^|6 /b
wZZ~!"O&
public class SiteInfoBean { N8pV[\f
.XqeO@z
HMC-^4\%[
private String sSiteURL; //Site's URL =n5n
private String sFilePath; //Saved File's Path _Dd>e=v
private String sFileName; //Saved File's Name #|4G,!
private int nSplitter; //Count of Splited Downloading File =\_gT=tZ
jz`3xFy *]
7Q]c=i cg
public SiteInfoBean() `LNhamp
{//nSplitter的缺省值为5 iGSA$U P|
//default value of nSplitter is 5 Y/6>OD
this("","","",5); `!t-$i
} ~|9VVeE
zz[fkH3
B2oKvgw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'da 'WZG
{ #bBh. ^
sSiteURL= sURL; UOsK(mB
sFilePath = sPath; #M{qMJHDo
sFileName = sName; ,#FP]$FK
this.nSplitter = nSpiltter; gyD;kn\CP
H<[~V0=
)l$}plT4
} $'I&u
D HT^.UM28
3rB0H
public String getSSiteURL() ,,BP}f+l$
{ =/_uk{
return sSiteURL; _XT'h;m
} $,2T~1tE
Bcarx<P-p
4xEw2F
public void setSSiteURL(String value) mE`qA*=?
{ SOq:!Qt
sSiteURL = value; W^H3=hZ
} 9sT5l"?g
$:%E<j4Dn
}04mJY[
public String getSFilePath() _crhBp5@T3
{ ka!v(j{E
return sFilePath; ,5"(m?[m
} aUzCKX%>C
oWL_Hh%-f`
u1L^INo/
public void setSFilePath(String value) }rI:pp^KS
{ p09p/
sFilePath = value; ?!&%-R6*
} C&>*~
@`dg:P*[
GE(~d'
public String getSFileName() 3PGAUQR#"q
{ _<LL@IX
return sFileName; @U18Dj[
} i4,p\rE0
BH1h2OEe#
w^ut,`yWR
public void setSFileName(String value) oR&z,%0wMK
{ jtlRom}
sFileName = value; ?T2>juf]5~
} nV7Vc;
o^vX\a?`u
E Izy
public int getNSplitter() .dk<?BI#H
{ 7Vsp<s9bj
return nSplitter; A$3Rbn}"
} R`cP%7K
o(oOB
a3<:F2=~\
public void setNSplitter(int nCount) @2/|rq
{ 1f}(=Hv{
nSplitter = nCount; uD>=
} N=BG0t$
} R ,qQC<
>< $LV&
WA8<:#{e
/* @wgd 3BU
**Utility.java #dj?^n g
*/ uy'seJ
package NetFox; )rK2%\Z
(tX3?[ii
+ODua@ULFB
public class Utility { OALNZKP
x_nwD"
WJOoDS!i
public Utility() (MI>7| ';
{ ~2"hh$
h<U?WtWT-p
+T$Olz
} &\N>N7/1
teg5g|*
//线程睡眠 HCs^?s8Pp
public static void sleep(int nSecond) gHLI>ew*QR
{ JP5e=Z<
try{ E(P 6s;LZ
Thread.sleep(nSecond); FKTF?4+\U
} ;"Kgg:K>W
catch(Exception e) D#b*M)X"
{ 8x U*j
e.printStackTrace (); -!Myw&*\V
} Kd`(^
} a)JXxst
g[O?wH-a
//日志 d fj23+
public static void log(String sMsg) N $) G8
{ W5 F\e[Ax5
System.err.println(sMsg); "Gp[.=.z?
} 985F(r
HE,L8S
K:a8}w>Up
public static void log(int sMsg) m!/TJhiQ
{ 2bNOn%!
System.err.println(sMsg); Cf=H~&`Z
} [i`
} LpU}.
V:kRr cX
.J)TIc__|A
/* T;/GHC`{Y
**TestMethod.java |#@7$#j
*/ ?8-!hU@QC
package NetFox; 'q-q4QCB
zl@^[km{
hy*{{f;
public class TestMethod { *8Z2zmZtR^
[CI&4)#
w(Z?j%b
public TestMethod() Sf*)Z3f
{ ///xx/weblogic60b2_win.exe ]nhh|q9r{
try{ NUFz'MPv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5l6/5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qNQ54#
SiteFileFetch fileFetch = new SiteFileFetch(bean); e^Zm09J
fileFetch.start(); VI2lwE3
} fHup&|.
catch(Exception e){e.printStackTrace ();} 4!/JN J
/| v.A\:
<kK>C8+
} 7AV{ h[J
2tq2
uQ5h5Cfz
public static void main(String[] args) -F~DOG%
{ d.wGO]"
new TestMethod(); Tc6cBe,
} IL].!9
} Z+El(f x
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