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)); An[*Jx
} <$Uj ~jN
for(int i=0;i<nEndPos.length-1;i++) ~uC4>+dk
{ 9z'</tJ`
nEndPos = nStartPos[i+1]; ":7cZ1VN2
} Yc?taL)
nEndPos[nEndPos.length-1] = nFileLength; /gy;~eB01
} D{'Na5(
} 1V+1i)+
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gyCb\y+\a
//启动子线程 tO[+O=d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CM5A-R90
for(int i=0;i<nStartPos.length;i++) .[1A
{ i'e^[oZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Bf'jXM{-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0M8JE9 Kx
nStartPos,nEndPos,i); '12|:t&7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0^E!P>
fileSplitterFetch.start(); i6`8yw
} +o'. !sRH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oN `tZ;a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %m+MEh"b5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n"FOCcTIs
nEndPos = " + nFileLength); n;Iey[7_E`
// fileSplitterFetch[nPos.length-1].start(); cWRB=`=qz
lf|^^2'*2<
huKz["]z[
//等待子线程结束 :!}zdeRJ
//int count = 0; "BFW&<1
//是否结束while循环 qsk71L
boolean breakWhile = false; 5\4>H6
r`B+ KQ4
~-:CN(U
while(!bStop) 3@"VS_;?
{ cF(9[8c{
write_nPos(); A+F-r_]}db
Utility.sleep(500); <}mT[;:"
breakWhile = true; *e>:K$r
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1|. 0]~0
for(int i=0;i<nStartPos.length;i++) epG;=\f}m`
{ w`7l;7[
if(!fileSplitterFetch.bDownOver) XdS<51 C
{ GUp51*#XR
breakWhile = false; +;!w;t
break; I9Sh~vTm=u
} 4Dd9cG,lN
} S}< <jI-z
if(breakWhile) GecXMAa:2
break; y]CJOC)/K
<Ihn1?
`nM4kt7
//count++; Q`s(T
//if(count>4) ~%}g"|o
// siteStop(); [`b{eLCFX]
} (qG$u&
uf>w*[m5
W ,U'hk%
System.err.println("文件下载结束！"); 3PEs$m9e
} "Jwz.,Y\
catch(Exception e){e.printStackTrace ();} \bsm#vY,
} ]e3nnS1*.
2?ednMoE
""a8eB6
//获得文件长度 DVS7N_cx2o
public long getFileSize() jFc{$#g-
{ A^Zs?<C-
int nFileLength = -1; 2~4C5@SxL
try{ B)|s.Ez
URL url = new URL(siteInfoBean.getSSiteURL()); Rq9gtx8,=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fi`:G}
httpConnection.setRequestProperty("User-Agent","NetFox"); h P1|l
*o#`lH
19vD(KC<
int responseCode=httpConnection.getResponseCode(); =e+go ]87x
if(responseCode>=400) {h=Ai[|l4Q
{ @hvq,[
processErrorCode(responseCode); [n"<(~
return -2; //-2 represent access is error ?`XKaD! f
} 'YeJGzsJp
s^ a`=kO
d]^i1
String sHeader; # 9t/j`{
EGt)tI&
vKt_z@{{L
for(int i=1;;i++) f,#xicSB*
{ N#:"X;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '$zFGq }}
//Utility.log(in.readLine()); ep!.kA=\
sHeader=httpConnection.getHeaderFieldKey(i); smU+:~
if(sHeader!=null) zyr6Tv61U
{ R[c_L=
if(sHeader.equals("Content-Length")) *8p</Q
{ D4|_?O3|m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e'Pa@]VaC
break; rUO{-R
} X@)lPr$a
} 8{YxUD
else Xwi&uyvU&
break; D/WS
} 2&m7pcls
} kWd'gftQ
catch(IOException e){e.printStackTrace ();} A M2M87{t
catch(Exception e){e.printStackTrace ();} ht|r+v-
>g&`g}xZQ
PwW@I~@>
Utility.log(nFileLength); :dzU]pk%0
E@FenCF
hqPn~Tq
return nFileLength; @2gMtf?<
} z@i4dC
)VT/kIq-U
<B`V
//保存下载信息（文件指针位置） b5Pn|5AVj
private void write_nPos() >gl.(b25C
{ F 4/Uu"J:
try{ +$t%L
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7,TWCVap
output.writeInt(nStartPos.length); }U9jsm
for(int i=0;i<nStartPos.length;i++) ' T]oV~H
{ L|LTsRIq
// output.writeLong(nPos); kdCOcJB
output.writeLong(fileSplitterFetch.nStartPos); I8?[@kg5b'
output.writeLong(fileSplitterFetch.nEndPos); dI-5%Um
} YkX=n{^
output.close(); d]EvC>
} 0K ?(xB
catch(IOException e){e.printStackTrace ();} _GqE'VX
catch(Exception e){e.printStackTrace ();} }=a4uCE
} "N]o5d
mx~sxYa
P~e$iBH'
//读取保存的下载信息（文件指针位置） Wi^rnr'Ss
private void read_nPos() 4&e@>
{ Wg^cj:&`u
try{ s.'\&B[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x[UO1% _o-
int nCount = input.readInt(); Nl`ry2"<
nStartPos = new long[nCount]; 070IBAk}_
nEndPos = new long[nCount]; GDp p`'\
for(int i=0;i<nStartPos.length;i++) Q/)ok$A&
{ OPW"ABJ
nStartPos = input.readLong(); `aL|qyrq#
nEndPos = input.readLong(); ~uadivli
} 493i*j5r)l
input.close(); nM-SDVFM
} "R@N|Qx'
catch(IOException e){e.printStackTrace ();} l-}5@D[
catch(Exception e){e.printStackTrace ();} AijTT%
} /v4S@SQ+
xc.D!Iav
h;qy5KS
private void processErrorCode(int nErrorCode) BWdc^
{ Wx$q:$h@q
System.err.println("Error Code : " + nErrorCode); Fx5d@WNa>
} '<< ~wt
v9m;vWp
ir:~*|
//停止文件下载 @B[Cc`IN"
public void siteStop() ]^jdO##M
{ 9,f<Nb(\
bStop = true; 9+ l3$
for(int i=0;i<nStartPos.length;i++) > ' 0 ][~
fileSplitterFetch.splitterStop(); <3=qLm
#0hNk%X=
fGf-fh;s
} .#55u+d,
} exO#>th1
//负责部分文件的抓取 )S};k=kG
**FileSplitterFetch.java $n Sh[{
*/ HJaw\zbL
package NetFox; {lTxB'W@d
i4zV(
bro
import java.io.*; H9VXsFTW
import java.net.*; lI_Yb:
>q@Sd
S=H_9io
public class FileSplitterFetch extends Thread { 7X{bB
w zqd g
BBR"HMa4
String sURL; //File URL 4 %)N(%u
long nStartPos; //File Snippet Start Position pq[X)]z|
long nEndPos; //File Snippet End Position Afy .3T @)
int nThreadID; //Thread's ID (y~laW!
boolean bDownOver = false; //Downing is over H >:4MY
boolean bStop = false; //Stop identical 7ec0Xh1
FileAccessI fileAccessI = null; //File Access interface /ggkb8<3
^+%tlX_+.
S2&9#6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yw.~trF&%
{ twtkH~`"Q
this.sURL = sURL; 3g0u#t{
this.nStartPos = nStart; l{6` k<J(
this.nEndPos = nEnd; ZEj!jWP2m
nThreadID = id; $xA J9_2P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _2m[(P9d
} w3<"g&n|
slge+xq\J
NSS4vtA
public void run() xaWGa1V'z
{ ,rZn`9
while(nStartPos < nEndPos && !bStop) m0|Ae@g~3
{ g=xv+e
,](v?v.[4
=_8 UZk.
try{ df4sOqU
URL url = new URL(sURL); lI4J=8O0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tE]5@b,R
httpConnection.setRequestProperty("User-Agent","NetFox"); 6Z(*cf/s
String sProperty = "bytes="+nStartPos+"-"; \D,M2vC~G
httpConnection.setRequestProperty("RANGE",sProperty); 0R@g(
Utility.log(sProperty); (_w %
G@!_ZM8h
?7yQ&p
InputStream input = httpConnection.getInputStream(); N7*CP|?E
//logResponseHead(httpConnection); 'Aj(i/CM
_%wK}eH+sy
~$4]HDg
byte[] b = new byte[1024]; psIkG0 &
int nRead; # 0GGc.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -F"d0a,
{ vpm ]9>1[
nStartPos += fileAccessI.write(b,0,nRead); (Sth:{;
//if(nThreadID == 1) vWU%ST
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _0,"vFdj
} ytjK++(T5
oGm1d{_-O
-3.UE^W2
Utility.log("Thread " + nThreadID + " is over!"); uAu( +zV2
bDownOver = true; ]alh_U
//nPos = fileAccessI.write (b,0,nRead); cMDRWh
} b fp,zs
catch(Exception e){e.printStackTrace ();} umQi
} bh6d./
} lPY@{1W
\ V6
CI,lkO|C
//打印回应的头信息 =~J"kC
public void logResponseHead(HttpURLConnection con) $ !v}xY
{ p?Ed- S
for(int i=1;;i++) $^}[g9]1
{ Yeqvv
String header=con.getHeaderFieldKey(i); }>V/H]B
if(header!=null) 5k69F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i{8]'fM
Utility.log(header+" : "+con.getHeaderField(header)); E;6~RM:
else Sv7 i! j
break; 9C_*3?6
} \e<mSR
} Iz#yQ`
t)9]<pN%
SD?BM-&~
public void splitterStop() &vCeLh:s
{ 2\VAmPG.Zs
bStop = true; V1<ow'^i
} h40'@u^W
8O6_iGTBh
U^[<
} R'SBd}1
u?F (1iN=
Y+g,pX
/* 9`B0fv Q&
**FileAccess.java eOt%xTx
*//文件访问(定位，写) SBTPTb
package NetFox; D9.`hs0
import java.io.*; vQ 4}WtvA
Bz+.Qa+
q +R*Hi
public class FileAccessI implements Serializable{ 7rcA[)<'
-/>9c-F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OUzR@$
RandomAccessFile oSavedFile; }taLk@T
long nPos; n#BvW,6J
icE|.[
,h^r:g
public FileAccessI() throws IOException o@9+mM"B)
{ :\b|dvI<
this("",0); O|I+],
} /Pvk),ca
f2yq8/J8.
gfde#T)S
public FileAccessI(String sName,long nPos) throws IOException =q+R
{ jH>8bXQqZ
oSavedFile = new RandomAccessFile(sName,"rw"); Q(Gyq:L=>
this.nPos = nPos; URA0ey`
oSavedFile.seek(nPos); Z~p!C/B
} qZ*f%L(
;F5"}x
?^9BMQ+
public synchronized int write(byte[] b,int nStart,int nLen) IkDiT63]I
{ x7dEo%j
int n = -1; /[K_ &
try{ XA<ozq'
oSavedFile.write(b,nStart,nLen); ZyI$M3{J
n = nLen; rkDi+D6`q
} T#EFXHPr
catch(IOException e) (}smW_`5
{ mnjs(x<m
e.printStackTrace (); E!J=8C.:
} ,%[4j9#!_
J;}3t!
7Xg?U'X
return n; D!F 2l_
} (ChD]PWQ
<*(^{a.O
n2f6p<8A
} h2~4G)J
HYCuK48F[_
tfYB_N
/* 6w|J-{2
**SiteInfoBean.java =\};it{u
*/ wL}l`fRB
package NetFox; mwC=o5O
epg#HNP7^Y
g/~XCC^F?
public class SiteInfoBean { sOBu7!G%
CMW,slC_3
Lrd[Ov
private String sSiteURL; //Site's URL +f|BiW
private String sFilePath; //Saved File's Path =*Z5!W'd
private String sFileName; //Saved File's Name z6*<V5<7
private int nSplitter; //Count of Splited Downloading File 2`?!+")
V}WB*bE
-e*ZCwQ
public SiteInfoBean() y<:<$22O
{//nSplitter的缺省值为5 (MLwQiop
//default value of nSplitter is 5 i-" p)2d=#
this("","","",5); #%lo;W~IY
} mGjN_
O|kOI?f
=(HeF.!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *L4`$@l8
{ 0Ua%DyJ
sSiteURL= sURL; #V,R >0"
sFilePath = sPath; c;2#,m^
sFileName = sName; KNLnn;l
this.nSplitter = nSpiltter; !C4!LZ0A
R?o$Y6}5
5=|hC3h
} r!PpUwod
dG7OqA:9
P!G858V(
public String getSSiteURL() GfEX>
{ cyyVg!+
return sSiteURL; )3Z ^h<"j
} Z;/$niY
<r#eL39I
4)|8Eu[p7
public void setSSiteURL(String value) >TkE~7?l
{ 4%nE*H%
sSiteURL = value; a`[uNgDO
} Qv,"($n\
%h?x!,q Y
1i[\T
public String getSFilePath() #9-P%%kQ
{ li~d?>
return sFilePath; FKNMtp[`
} CHrFM@CM
$6OkIP.
~T&<CTh
public void setSFilePath(String value) (q+)'H%iK
{ "#[!/\=?:
sFilePath = value; = C4
} )OiT{-m
C{gyj}5
x=ul&|^7D
public String getSFileName() wr[,
{ X.hm s?]
return sFileName; 3;S,3
} CC#;c1t
\jOA+FU[
8GvJ0Jq}U
public void setSFileName(String value) `c<;DhNO
{ ZovW0Q)m
sFileName = value; {&jb5-*f
} N[<\>Ps|u
+L7n<U3
b0lq\9
public int getNSplitter() q Y#n'&
{ S H!
return nSplitter; "jG}B.l=,
} N[s}qmPha
^$b Y,CE
{q"OM*L(
public void setNSplitter(int nCount) G1vNt7
{ N<~t3/Nm
nSplitter = nCount; e" St_z(
} SHe49!RA'{
} _lamn}(x0
ILGMMA_2
|Y?HA&
/* "wNJ
**Utility.java N@t|7~
*/ Wk)OkIFR
package NetFox; 0*f)=Q'
~_/(t'9
G"h'_7
public class Utility { wne,e's}
!@}wDt
uG,5BV.M
public Utility() ML|FQ
{ k?+?v?I =
)h7<?@wv&
%5(I/zB
} U|jSa,}
PGqQ@6B
//线程睡眠 \W~N
public static void sleep(int nSecond) ,J+}rPe"sf
{ 1*\o.
try{ 8WXQOo8
Thread.sleep(nSecond); M/b Sud?@%
} 8Vr%n2M
catch(Exception e) 6 (]Dh;gC
{ l3)}qu
e.printStackTrace (); "&Y`+0S8
} V<GHpFi0
} h`^jyoF"(
!|^|,"A)
//日志 Mk"^?%PxT
public static void log(String sMsg) |-:()yxs
{ p{r}?a
System.err.println(sMsg); Hj^1or3R]
} C5o#i*|
(A9Fhun
d;boIP`M;
public static void log(int sMsg) @>,^":`#
{ Fs9!S a7v
System.err.println(sMsg); 01t1Z}!y
} |d{PA.@33
} p`olCp'
cr7 }^s
5_GYrR2
/* rV` #[d
**TestMethod.java 11Q1AN
*/ dqU~`b9
package NetFox; fK>L!=Q
?WGA?J %2
rBQ_iB_
public class TestMethod { R0KPZv-
<sb~ ^B
Yl Zso2
public TestMethod() - YEZ]:"
{ ///xx/weblogic60b2_win.exe W!Gq.M
try{ n@<YI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D+rxT: d
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^UP`%egR
SiteFileFetch fileFetch = new SiteFileFetch(bean); LBw1g<&
fileFetch.start(); cN/6SGHK
} Wf+cDpK
catch(Exception e){e.printStackTrace ();} [_BP)e
G30-^Tr
qU \w=
} zVViLUwG
is?{MJZ_
(~p< P+
public static void main(String[] args) {:/#Nc$5
{ j`{?OYD
new TestMethod(); yuh *
} E^B'4
} x+\`gK5
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