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)); ;1PnbU b
} U, _nEx
for(int i=0;i<nEndPos.length-1;i++) >MD['=J[d
{ LdxrS5
nEndPos = nStartPos[i+1]; C5oslP/@
} #G2~#\
nEndPos[nEndPos.length-1] = nFileLength; jf25Ky~
} ({JXv
} "]h4L
<>JN&#3?
c ;_ T
//启动子线程 3\_ae2GW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Pf&\2_H3s9
for(int i=0;i<nStartPos.length;i++) .%)FK#s-
{ 3db ,6R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IsjxD|u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), PqV9k,5f
nStartPos,nEndPos,i); V|GH4DT=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I^erMQn[ z
fileSplitterFetch.start(); _~V7m
} d 7vD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4FSA:]o-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I\djZG$s;N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1OB,UU"S$
nEndPos = " + nFileLength); OUCLtn\
// fileSplitterFetch[nPos.length-1].start(); 'p<lfT
YjaEKM8*
(B|4wR\
//等待子线程结束 4CA(` _i~
//int count = 0; '.Iz*%"
//是否结束while循环 k"_i7
boolean breakWhile = false; :lj1[q:Y>
'&/ 35d9|*
O[ tD7!1
while(!bStop) htC~BK3(
{ {A2EGUmF2
write_nPos(); Bk,:a,
Utility.sleep(500); Co[fq3iX#
breakWhile = true; `-a](0QU
2d:<P!B
B-Bgk
for(int i=0;i<nStartPos.length;i++) Gx Z'"x
{ TG4?"0`I5
if(!fileSplitterFetch.bDownOver) B#RBR<MFC
{ #OlU|I
breakWhile = false; n8W+q~sW%
break; kA3nhBH
} :`('lrq
} Qtj.@CGB
if(breakWhile) eeKErpj8A
break; zN}1Qh
/{Ff)<Q.Z
I5EKS0MQ!
//count++; *sNZ.Y:.
//if(count>4) R^8L^8EL
// siteStop(); D7q%rO|F'
} lmmB=F
&'%b1CbE
'a]4]d
System.err.println("文件下载结束！"); dkTewT6'
} M"cB6{st[
catch(Exception e){e.printStackTrace ();} #4hxbRN
} tA#7Xr+
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,/{(8hn
//获得文件长度 /S4$qr cM
public long getFileSize() j1/.3\
{ u,h,;'J
int nFileLength = -1; +um Ua
try{ L~x PIu
URL url = new URL(siteInfoBean.getSSiteURL()); qg521o$*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $ = uz
httpConnection.setRequestProperty("User-Agent","NetFox"); b6KO_s:'g
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int responseCode=httpConnection.getResponseCode(); =W+ h.?
if(responseCode>=400) E?$|`<o{|`
{ %:61@<
processErrorCode(responseCode); tE&@U$0>o
return -2; //-2 represent access is error ""AP-7
} BS-nny
w[`2t{^j
Po+I!TL'
String sHeader; y3!r;>2k=
Fk&W*<}/;
5Q_T=TL
for(int i=1;;i++) )=,%iL-
{ h7],/? s
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n*%o!=
//Utility.log(in.readLine()); rHS;wT
sHeader=httpConnection.getHeaderFieldKey(i); =E{e|(1+u
if(sHeader!=null) >lyX";X#
{ 05$;7xnf(
if(sHeader.equals("Content-Length")) W lDcKY
{ sZ~q|}D-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;Y/{q B!
break; um/2.Sn>
} $U3|.4
} SZ/}2_;
else Xr?(w(3
break; 2oY.MQD7iW
} U[l7n3Y=
} PwF 1Pr`r
catch(IOException e){e.printStackTrace ();} >F@qFPN]
catch(Exception e){e.printStackTrace ();} 4 h}03 oG
+TA'P$j
\BIa:}9O
Utility.log(nFileLength); +w'"N
x#wkODLqi
m8Wv46%
return nFileLength; n^} -k'l
} z ^e99dz
Z )Imj&;
fW/G_
//保存下载信息（文件指针位置） ixK&E#
private void write_nPos() XUI9)Ne
{ 4!%@{H`3
try{ =bn(9Gm!J
output = new DataOutputStream(new FileOutputStream(tmpFile)); dv?ael^
output.writeInt(nStartPos.length); ^,P# <,D,
for(int i=0;i<nStartPos.length;i++) ->BGeP_=|
{ Y|'0bujr
// output.writeLong(nPos); M%*D}s-QE
output.writeLong(fileSplitterFetch.nStartPos); HR.^ y$IE
output.writeLong(fileSplitterFetch.nEndPos); X@ zw;Se
} yH\3*#+
output.close(); B=EI&+F+
} |rjHH<
catch(IOException e){e.printStackTrace ();} O=,[u?
catch(Exception e){e.printStackTrace ();} _J|TCm
} [#+yL
QNH-b9u>8
nRP|Qt7>
//读取保存的下载信息（文件指针位置） l|, Hj
private void read_nPos() NNKI+!vg
{ Z&f@)j
try{ )K=%s%3h<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3K8#,TK3
int nCount = input.readInt(); 5y 9(<}z
nStartPos = new long[nCount]; @W4tnM,#
nEndPos = new long[nCount]; .G ^-.p
for(int i=0;i<nStartPos.length;i++) HDmjt+3&n
{ {}sF?wZf
nStartPos = input.readLong(); gD13(G98
nEndPos = input.readLong(); <7U\@si4
} 2)iwAu
input.close(); +ESEAi91
} M2pe*z
catch(IOException e){e.printStackTrace ();} >9WJa5{
catch(Exception e){e.printStackTrace ();} SG5GJCkc
} [`F}<L."
4AIo,{(
5%qq#;[n
private void processErrorCode(int nErrorCode) {D6p?TL+
{ 9.:]eL
System.err.println("Error Code : " + nErrorCode); n@TK}?\UoR
} Su4&qY
Aof)WKo
QR ?JN\%?
//停止文件下载 nrhzNW>]
public void siteStop() :4Gc'bR
{ qjcPJ
bStop = true; @r.w+E=
for(int i=0;i<nStartPos.length;i++) &oz^dlw
fileSplitterFetch.splitterStop(); Az+k8=?
u<g0oEs)
r<%ua6@
} H^VNw1.
} lQ8h-Tz
//负责部分文件的抓取 h_( #U)z_3
**FileSplitterFetch.java [NxC7p:Lo
*/ BR*'SF\T
package NetFox; 4# L}&
d@0p<at>~
s6DmZ^Y%
import java.io.*; xJ$/#UdP
import java.net.*; Q.U wtH
J1s~w`,
Jbv[Ql#
public class FileSplitterFetch extends Thread { R&-Vm3mc3
&x":
'%H\k5^
String sURL; //File URL zu,F 0;De
long nStartPos; //File Snippet Start Position Nf]h8d~
long nEndPos; //File Snippet End Position [$Dzf<0
int nThreadID; //Thread's ID /e:kBjysJ
boolean bDownOver = false; //Downing is over V 6*ohC:
boolean bStop = false; //Stop identical (u{?aG~
FileAccessI fileAccessI = null; //File Access interface h7P<3m}
n@JZ2K4
'^{:HR#i
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +55+%oGl
{ f@j)t%mh
this.sURL = sURL; _.{I1*6Y2
this.nStartPos = nStart; qk{+Y
this.nEndPos = nEnd; @W1F4HYds
nThreadID = id; m8T< x>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n9%&HDl4
} 9n#lDL O
*QGyF`Go{
5r)]o'?s
public void run() V JJ6q
{ 6CV9ewr
while(nStartPos < nEndPos && !bStop) m]?C @ina
{ \) FFV-k5
Hrg~<-.La
;:]#Isq
try{ 3J_BuMV
URL url = new URL(sURL); A<U9$"j9J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F1q6 3
httpConnection.setRequestProperty("User-Agent","NetFox"); tkX?iqKQ
String sProperty = "bytes="+nStartPos+"-"; s=H|^v
httpConnection.setRequestProperty("RANGE",sProperty); 8#{DBWU
Utility.log(sProperty); _C%:AFPP>
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9 WO|g[Y3
InputStream input = httpConnection.getInputStream(); [["az'Lrk?
//logResponseHead(httpConnection); IA;'5IF
c gOkm}h
Bnfp_SM
byte[] b = new byte[1024]; _)U.5f<
int nRead; s L=}d[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6Bf aB:
{ mUdj2vB$+'
nStartPos += fileAccessI.write(b,0,nRead); i",7<01
//if(nThreadID == 1) 8W2oGL6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rizWaw5E!8
} 0,]m.)ws
f.G"[p
J3z:U&%=
Utility.log("Thread " + nThreadID + " is over!"); \0fk^
bDownOver = true; #/0d
//nPos = fileAccessI.write (b,0,nRead); n)uck5
} M-V{(
catch(Exception e){e.printStackTrace ();} \\)9QP?
} O63:t$Yx#
} UbEK2&q/8
.Y5o&at6s
EXEB A&*
//打印回应的头信息 4de:hE
public void logResponseHead(HttpURLConnection con) !Z!X]F-fY
{ j[${h,p?
for(int i=1;;i++) KQTv5|$?
{ $1uT`>%
String header=con.getHeaderFieldKey(i); HZ[.,DuW
if(header!=null) K"/3/`T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +GvPJI
Utility.log(header+" : "+con.getHeaderField(header)); +A-z>T(
else #GuN.`__n,
break; -R-yr.$j*
} \~> .NH-
} _J X>#h
`{1~]?-&
@q"HZO[
public void splitterStop() y#{v\h Cz
{ _KJ!C!
bStop = true; 0^83:C ^{
} \h@3dJ4
awl3|k/
}0}=-g&
} dT7!+)s5-
;R([w4[~
3_ ZlZ_Tq
/* [tk6Kx8a
**FileAccess.java .$ X|96~$
*//文件访问(定位，写) WRp0.
package NetFox; dUH+7.\
import java.io.*; Yy'CBIq#f
=`ECM7
\YPvpUg
public class FileAccessI implements Serializable{ -<l2 $&KS
Wi@YJ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oV'G67W
RandomAccessFile oSavedFile; I+/fX0-Lib
long nPos; :E.T2na
!;Vqs/E
hrW2#v
public FileAccessI() throws IOException 8 .t3`FGH
{ %J8uVD.2
this("",0); Ip|=NQL>
} k_`h (R
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snYyxi
public FileAccessI(String sName,long nPos) throws IOException j@R"AP}
{ * .g[vCy
oSavedFile = new RandomAccessFile(sName,"rw"); WOQ>]Z
this.nPos = nPos; gKP=@v%-
oSavedFile.seek(nPos); 8GeJ%^0o}
} 3qkPe_<I
#$;}-*
@RHG@{x{K
public synchronized int write(byte[] b,int nStart,int nLen) ~3)d?{5
{ "fC>]iA8I
int n = -1; I2WWhsNC
try{ {_4`0J`3
oSavedFile.write(b,nStart,nLen); >en\:pJn)'
n = nLen; On0,#i=
} <;*w97n
catch(IOException e) u6Yp,!+
{ TN/y4(j
e.printStackTrace (); 3e9UDN2
} m=25HH7enb
^% L;FGaA
hi/Z>1ZOX
return n; (aLjW=
} n&2OfBJ
W5/|.}
sB5@6[VDI
} gs&F .n
nrR2U`
6mqp`x`
/* QjKh#sU&
**SiteInfoBean.java urg^>n4V]
*/ *M.,Yoj
package NetFox; n#sK31;yb
QO:Z8{21So
[X7gP4
public class SiteInfoBean { 1p8pH$j'
S9[Y1qH>K
P(!%Pp
private String sSiteURL; //Site's URL dL~^C I
private String sFilePath; //Saved File's Path *z};&UsF{
private String sFileName; //Saved File's Name I|wC`VgB
private int nSplitter; //Count of Splited Downloading File B`YD>oCN
CwD=nT5`
Vjd(Z
public SiteInfoBean() {Wndp%
{//nSplitter的缺省值为5 j`#H%2W\;
//default value of nSplitter is 5 %Fx^"
this("","","",5); yqH9*&KH{
} g_JQW(_
gvr&7=p
!>f:wk2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -s0\4
{ B|.A6:1g+
sSiteURL= sURL; }a;H2&bu
sFilePath = sPath; egAYJK-,!
sFileName = sName; qcC(#0A>
this.nSplitter = nSpiltter; !<out4Mz"
WcY$=\7
P)Rq\1:
} Q.fUpa v
NLu[<u U*
JXHf$k
public String getSSiteURL() P/xEn_*v
{ BF 0#G2`h>
return sSiteURL; `KZu/r-M9
} K'B*D*w
zN9#qlfv
^Vi{._r
public void setSSiteURL(String value) gjx-tp 1.
{ qMoo#UX
sSiteURL = value; -3 Sb%V\
} ]$#9B-uB
SAdo9m'
-q8l"i>h=
public String getSFilePath() ^j2ve's:
{ L c )i
return sFilePath; >cpv4Pgm
} $@l=FV_;
yo8mfH_,
s>W :vV@
public void setSFilePath(String value) *U}-Y*
{ #U4 f9.FY*
sFilePath = value; N3zZ>#{
} )!U@:x\K
=[zP
^nK7&]rK
public String getSFileName() DWEDL[{
{ e1y#p3 @d
return sFileName; (BngwLVDK
} )CHXfO w
jT/P+2hMW
p2< 927z
public void setSFileName(String value) 4>HaKJ-c#
{ j5og}Pq:
sFileName = value; g7^|(!Y%
} !D?(}nag
@eutp`xoT\
>?_}NZ,y
public int getNSplitter() y^[t3XA6Q
{ 9_4(}|"N|
return nSplitter; :pNS$g[
} .R#-u/6g(
U#bmMH
Ya>AI.!K
public void setNSplitter(int nCount) [qxU \OSC
{ Vf.*!`UH
nSplitter = nCount; \B:k|Pw6~
} We\i0zUU
} s:iBl/N}
c`&g.s@N\
R4T@ ]l&W
/* bg/=P>2
**Utility.java P{BW^kAdH
*/ D?UURURf
package NetFox; W /*?y&
2(x| %
X @pm!c#
public class Utility { ExN$J
t: oQHhO?
gz~ug35
public Utility() Jt#HbAY
{ +0j{$MPZ
Zy.A9Bh~
h_\( $"
} CBNt _y
mIp> ~
//线程睡眠 ~:PM_o*6
public static void sleep(int nSecond) oO`a{n-
{ 'U*#71S
try{ dh.{lvlX|
Thread.sleep(nSecond); jl]3B
} Yyd]s\W
catch(Exception e) {:b~^yW
{ Ju&FwY+
e.printStackTrace (); ylb)SXBf
} wc~s:
} mP/#hwzB&q
wnK6jMjkSf
//日志 9+$IulOvk
public static void log(String sMsg) 2+?W{yAEi
{ *DXX*9 0
System.err.println(sMsg); ?B$L'i[l
} F6{/iF
isdNW l
<RpTk*Yo^=
public static void log(int sMsg) PkZ1Db
{ U$y wO4.
System.err.println(sMsg); T8)X?>CIW
} 3$Vx8:Rhdn
} -ah)/5j
S:Jg#1rww-
]=ZPSLuEm%
/* 'h7x@[|
**TestMethod.java if*~cPnN
*/ aMxj{*v7
package NetFox; ~l?c.CSd
N$v_z>6Z
_L` uCjA
public class TestMethod { zUDXkG*Lv
Qds:*]vGS
UZmUYSu;
public TestMethod() ->o[ S0
{ ///xx/weblogic60b2_win.exe r$-P
try{ %Y0BPTt$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =cb!2%?}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5O]ZX3z>
SiteFileFetch fileFetch = new SiteFileFetch(bean); WNb2"W
fileFetch.start(); sZxTsUW
} e=p_qhBt
catch(Exception e){e.printStackTrace ();} 6rWq hIaI
R,["w98a
\ltS~EuWU
} xLLTp7b(
'p\&Mc_Gu
Cg%Owe/E?0
public static void main(String[] args) ki}Li*)7
{ Y~Vc|zM^(
new TestMethod(); |pbetA4&
} _(~LXk^C
} Y2tBFeWY
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