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)); DnFzCJ
} eb}P/
for(int i=0;i<nEndPos.length-1;i++) *!ng)3#
{ .}/8]
nEndPos = nStartPos[i+1]; }%8ZN :
} 0cE9O9kE
nEndPos[nEndPos.length-1] = nFileLength; p<=Lh47 =
} mf3,V|>[\
} &hO-6(^I
cZQ8[I
W~0rSVD$<z
//启动子线程 5h&sdzfG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =T,Q7Dh
for(int i=0;i<nStartPos.length;i++) 9-/q-,
{ aTTkj\4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gk{ 'U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VaY#_80$s
nStartPos,nEndPos,i); k9f|R*LM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (0H=f6N
fileSplitterFetch.start(); |67Jw2
} mLqqo2u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zQ|2D*W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fJ[ ^_,O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3fhY+$tq
nEndPos = " + nFileLength); Q $}#&
// fileSplitterFetch[nPos.length-1].start(); \0x>#ygX
} Xo#/9
["<Xh0_
//等待子线程结束 @T~XwJ~
//int count = 0; dazNwn
//是否结束while循环 Tc/^h4xH
boolean breakWhile = false; u"=]cBRWL6
j*<J&/luYZ
[j-?)
while(!bStop) n2bhCd]j<b
{ iRnjN
write_nPos(); \ saV8U7B
Utility.sleep(500); pOXI*0_g.
breakWhile = true; "D _r</b
=^rt?F4
K2zln_W
for(int i=0;i<nStartPos.length;i++) ywAvqT,
{ dGYR 'x
if(!fileSplitterFetch.bDownOver) Jg;[k
{ @01.Pd
breakWhile = false; iHGVR
break; A.vAk''(}+
} Ze~P6
} Uv(R^50>
if(breakWhile) 22ON=NN
break; ZPmqoR[
J:N(U0U
<"5l<E
//count++; 94+^K=lAX
//if(count>4) }ouGxs+^[
// siteStop(); {&n- @$?
} ~i"=:D
F<,pAxl~@
3p=Xv%xd
System.err.println("文件下载结束！"); (Lgea
} v:P]o9Oj8
catch(Exception e){e.printStackTrace ();} +d6onO{8
} v1,#7sAW'
N.JR($N$
-xHR6
//获得文件长度 ;DuVb2~+
public long getFileSize() '#f<wfn
{ Iw`tbN L[
int nFileLength = -1; .D 4G;=Q
try{ x"Ky_P~
URL url = new URL(siteInfoBean.getSSiteURL()); <R]m(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {s mk<NL
httpConnection.setRequestProperty("User-Agent","NetFox"); u2oS Ci
zWC| Qe
L;RE5YrH%6
int responseCode=httpConnection.getResponseCode(); lgaSIXDK
if(responseCode>=400) #"N60T@
{ $pES>>P
processErrorCode(responseCode); LL#REK|lm8
return -2; //-2 represent access is error _ p\L,No
} [[ie
GQtNk<?$I
i!%bz
String sHeader; uvbVb"\"Yk
$xWwI(SaB
eL}w{Hlk T
for(int i=1;;i++) CT[9=wV)m%
{ rtuaU=U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y(J~:"}7)
//Utility.log(in.readLine()); e]RzvWq
sHeader=httpConnection.getHeaderFieldKey(i); o pTXI*QA
if(sHeader!=null) |fgUW.
{ Y)1/fEM
if(sHeader.equals("Content-Length")) )%K<pIk
{ !zX()V
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #hxYB
break; 5skN'*oG
} 9-;-jnDy
} 4aS}b3=n
else Z\nDR|3
break; A9.TRKb=8
} vha9,5_
} xsH1)
catch(IOException e){e.printStackTrace ();} #dZs[R7h
catch(Exception e){e.printStackTrace ();} 1C<cwd;9
Te-p0x?G.
n5$#M
Utility.log(nFileLength); [7vV#s3kJ
Uj(0M;#%o+
-!PJHCLd
return nFileLength; j}^w:W76
} o]<Z3)
~!$"J}d}<
,&_H
//保存下载信息（文件指针位置） axnlI*!
private void write_nPos() aJ+V]WmA
{ pp@ Owpb
try{ V'i-pn2gyu
output = new DataOutputStream(new FileOutputStream(tmpFile)); H>CbMz1u
output.writeInt(nStartPos.length); =Wcvb?;*
for(int i=0;i<nStartPos.length;i++) 7_I83$p'
{ l8oaDL\f
// output.writeLong(nPos); ^p3GT6
output.writeLong(fileSplitterFetch.nStartPos); "W7|Xp
output.writeLong(fileSplitterFetch.nEndPos); `WayR^9
} ab6I*DbF
output.close(); e$~[\ w
} d6J/)nl
catch(IOException e){e.printStackTrace ();} ' h7Faj
catch(Exception e){e.printStackTrace ();} QF>T)1&J[7
} 8qyEHUN2q
UMGiJO\yH
0fOhCxtL@
//读取保存的下载信息（文件指针位置） ]*=4>(F[
private void read_nPos() /.SG? 5t4
{ '`2KLO>!
try{ %>m.Z#R(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); AQ'%}(#0
int nCount = input.readInt(); I){4MoH.
nStartPos = new long[nCount]; ,Pa*; o\
nEndPos = new long[nCount]; X!]v4ma`
for(int i=0;i<nStartPos.length;i++) O <Rh[Aqn
{ `==l2AX
nStartPos = input.readLong(); XO <0;9|
nEndPos = input.readLong(); h5P_kZJ
} ;XN|dq
input.close(); "8f4s|@3
} P6v ANL-B
catch(IOException e){e.printStackTrace ();} {M**a
catch(Exception e){e.printStackTrace ();} 4m0^ N
} +hN>Q$E
zy,SL |6:
fmW{c mr|
private void processErrorCode(int nErrorCode) RDdnOzx
{ 3}|[<^$
System.err.println("Error Code : " + nErrorCode); ,\M77V
} Y^+x<
U,#~9
]X6<yzu&+l
//停止文件下载 p\&O;48=
public void siteStop() D4L&6[W
{ Bv<gVt
bStop = true; %,@pV%2
for(int i=0;i<nStartPos.length;i++) _*o<<C\E
fileSplitterFetch.splitterStop(); Xz^nm\
^^b'tP1>
.a@12J(I
} V%8(zt
} mUg :<.^
//负责部分文件的抓取 dxX`\{E
**FileSplitterFetch.java ]hS:0QE
*/ m4/qxm"Dx:
package NetFox; qZd*'ki<
`Z;Z^c
'[#y|
import java.io.*; u9"=t
import java.net.*; |3]/CrR_
~Zr}QO}G
GAj%o]}u
public class FileSplitterFetch extends Thread { P73GH
qX@e+&4P0
99=~vNn
String sURL; //File URL %/A>'p,~
long nStartPos; //File Snippet Start Position KfiSQ!{
long nEndPos; //File Snippet End Position ?#z$(upQ
int nThreadID; //Thread's ID Py;5z
boolean bDownOver = false; //Downing is over 6}6Q:V|
boolean bStop = false; //Stop identical ?06gu1z/
FileAccessI fileAccessI = null; //File Access interface 5Y *4a%"
6|eqQ+(A
a`'>VCg
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ozRO:*51
{ +YvF+E
this.sURL = sURL; #tV1?q
this.nStartPos = nStart; M/W"M9u
this.nEndPos = nEnd; o|@0.H|
nThreadID = id; =o9s?vOJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s;vt2>;q+e
} =Kkqk
AX v q~XE
uyYV_Q0~;
public void run() j.&dHtp
{ t(3f} ?
while(nStartPos < nEndPos && !bStop) 2_wue49-l
{ dL0Q8d\^T
6&$.E! z
$'V^_|EL7
try{ _pTcSp3
URL url = new URL(sURL); ps<Ef
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XM:BMd|
httpConnection.setRequestProperty("User-Agent","NetFox"); 0f@+o}i=)
String sProperty = "bytes="+nStartPos+"-"; uY5|Nmiu
httpConnection.setRequestProperty("RANGE",sProperty); )V1xL_hx/
Utility.log(sProperty); . Vb|le(7
@[;'b$T$
64u(X^i
InputStream input = httpConnection.getInputStream(); G=cRdiy`C
//logResponseHead(httpConnection); t<v.rb
:`N&BV
5=?P6I_$G
byte[] b = new byte[1024]; hQ|mow@Zmz
int nRead; 5k0iVpjQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _m9k2[N!
{ oLoc jj~T
nStartPos += fileAccessI.write(b,0,nRead); @6"MhF
//if(nThreadID == 1) liS'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b=EI?XwJ
} !P{ /;Q
'/I`dj
cNd&C'/N
Utility.log("Thread " + nThreadID + " is over!"); NZ1B#PG,c
bDownOver = true; {bXN[=j
//nPos = fileAccessI.write (b,0,nRead); q1VKoKb6\:
} T~xVHk1
catch(Exception e){e.printStackTrace ();} |qX?F`
} a[K&;)
} L/u|90)L
x"z\d,O%W
Ir JSU_
//打印回应的头信息 >>{):r Z
public void logResponseHead(HttpURLConnection con) R[m-jUL
{ ?^~ZsOd8B
for(int i=1;;i++) PlB3"{}0Q
{ *O$|,EsY
String header=con.getHeaderFieldKey(i); A"7YkOfwH
if(header!=null) XCI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D|5mNX%e
Utility.log(header+" : "+con.getHeaderField(header)); A$wC!P|;
else Y!M0JSaM
break; %G!!0V!
} *P'X[z
} p7YYAh@x\
Osqk#Oh
lj]M 1zEz&
public void splitterStop() "e-Y?_S7R8
{ .JKH=?~\
bStop = true; JzEg`Sn^
} E{V?[HcWq
T9c7cp[
U '{PpZ
} &0T.o,&y
x@Gg fH<l
M5VW1Ns
/* ^KbR@Ah
**FileAccess.java Vs"b
*//文件访问(定位，写) P.YT/
package NetFox; 5mAb9F8@
import java.io.*; CG%bZco((
"w"a0nv
a~yiLq
public class FileAccessI implements Serializable{ Kz;Ar&^`N
sNx_9pJs4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W7!Rf7TK
RandomAccessFile oSavedFile; - egTZW-
long nPos; uYebRCdR
boiP_*|MY
4(htdn6\
public FileAccessI() throws IOException qq!ZYWy2
{ wp~}1]g
this("",0); l=xG<)Okb
} c7+6[y DVE
7NJl+*u
d>Tv?'o`q
public FileAccessI(String sName,long nPos) throws IOException <7y/)b@
{ o+x%q<e;c
oSavedFile = new RandomAccessFile(sName,"rw"); pS8\B
this.nPos = nPos; ]n4PM=hz
oSavedFile.seek(nPos); ;C-ds
} }h1BAKg
FtJaX])b
!Mw/j`*
public synchronized int write(byte[] b,int nStart,int nLen) ,xU#uyB
{ iU+SXsXLR4
int n = -1; 3sV$#l P
try{ =RUy4+0>F
oSavedFile.write(b,nStart,nLen); 6`2i'flv
n = nLen; FqJd
} qVU<jt
catch(IOException e) Q7u|^Gu,5
{ &</)k|.A6\
e.printStackTrace (); =H7p&DhD[
} OR&pGoW
4j;IyQDvM
qdQ4%,E[
return n; Vw;iE=L
} < R"Y^]P=
PoZ$3V$(Lz
fKEDe>B5
} %(s|
=X(N+(1~
yPfx!9B
/* yuC"V'
**SiteInfoBean.java `/1rZ#
*/ Q:)4
package NetFox; QH><! sa
VP< zOk7
6MOwn*%5k
public class SiteInfoBean { 2L^/\!V#
e3n^$'/\r
&LM@xt4"^[
private String sSiteURL; //Site's URL #HL$`&m
private String sFilePath; //Saved File's Path 0qR#o/~I
private String sFileName; //Saved File's Name >#dLT~[\a
private int nSplitter; //Count of Splited Downloading File 3^Is4H_8
tY#&_%W
#}.{|'L
public SiteInfoBean() R;AcAJ;
{//nSplitter的缺省值为5 @}jg5}
//default value of nSplitter is 5 `Zp*?
this("","","",5); (M;d*gNr
} 5<X"+`=9
>l}v _k*~B
8Ud.t=2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3q'nO-KJ
{ ral=`/p
sSiteURL= sURL; qKXg'1#E)
sFilePath = sPath; v+EJ $
sFileName = sName; -DGuaUU
this.nSplitter = nSpiltter; F+c8 O
%Lx#7bR U
/slCK4vFc
} H1~9f{
DB"z93Mr<K
,P`:`XQ>_B
public String getSSiteURL() LP7jCt
{ =WF@S1
return sSiteURL; Fu?_<G%Ynp
} eOVln1a
Lniz>gSc
;U0w<>4L
public void setSSiteURL(String value) J}Z\I Y,
{ O 8l`1
sSiteURL = value; 0(5qVJ12
} 3#fg 2
b7'A5]X
cooicKS7
public String getSFilePath() *W=1yPP
{ Qt"jU+Zoy
return sFilePath; ko!]vHB9`
} fZs}u<3Q)
!j6CvclT
FBi&MZ`
public void setSFilePath(String value) n%2c<@p#
{ BDL[C<d(
sFilePath = value; (CAVOed
} ,o2x,I
).Z U0fV
f U<<GK70
public String getSFileName() `)=sQ2P
{ fuf'r>1n
return sFileName; Cs]\3R|D`
} J{;\TNkJ
"2!5g)iO
q.hpnE~#lh
public void setSFileName(String value) W)2k>cS
{ KVC18"|f
sFileName = value; aB&a#^5CI
} gW G>}M@
\= 6dF,V
x;JC{d#
public int getNSplitter() x'i~o'
{ aE]RVyG@L
return nSplitter; t:'^pYN:g
} 'eQ*?a43
;x)f;!e+
9D5v0Qi
public void setNSplitter(int nCount) h^zcM_
{ )x,-O#"A
nSplitter = nCount; 5p.#nc!;y
} lA,[&
} >U:.5Tch'V
O8*yho
c~Y g(
/* KWVl7Kw#e
**Utility.java -<\hcV`&
*/ K?S5C8
package NetFox; /u'V>=D;f
6 #jpA.;
cW{Bsr
public class Utility { & @$D(
1VXn`O?LW
(Kkqyrb
public Utility() #9(iu S+BU
{ ;|vn;s/
St3/mDtH
!J}Q%i
} {us#(4O
9Kc;]2m
//线程睡眠 meD?<g4n~"
public static void sleep(int nSecond) s9b+uUt%
{ e>HdJ"S`
try{ t; #D,gx
Thread.sleep(nSecond); ?D@WXE0a
} p ^I#9(PT
catch(Exception e) ]1bNcq2I
{ eeUEqM$7EX
e.printStackTrace (); L# .vbf
} Ap(>mUs!i
} Qv;^nj{\qV
3r2e_?m
//日志 ^hwTnW9Z1:
public static void log(String sMsg) ;`Wh^Qgi
{ }@A{'q5y
System.err.println(sMsg); >@|XY<
} sc# q03
|/RZGC4
u$V@akk
public static void log(int sMsg) yMe;
{ DUs0L\
System.err.println(sMsg); ,h9N,bIQg
} Y7@$#/1
} ]%6XE)
<`=(Ui$fD
O&PrO+&
/* Z-'xJq
**TestMethod.java "&TN}SBW
*/ wn>?r ?KIB
package NetFox; lDtl6r/
Ix+\oq,O
{r[g.@
public class TestMethod { :}~B;s0M\
,uhOf! |
k%sh;1.
public TestMethod() uRRp8hht
{ ///xx/weblogic60b2_win.exe $mDlS
try{ OO?BN!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _Dg|Iz,Uh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Pu0O6@Rg
SiteFileFetch fileFetch = new SiteFileFetch(bean); I(0 *cWO
fileFetch.start(); a*UxRi8
} !L55S03
catch(Exception e){e.printStackTrace ();} ty)~]!tA
sy+tLDMd
%1PNP<3r0
} :J;*]o:
{$qLMx';
+m1y#|08
public static void main(String[] args) R(cM4T.a
{ MN. $a9m
new TestMethod(); r|0wIpi6Q
} :"~n` Q2[
} >Byxb./*
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