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)); {Q8DPkW
} .E|Hk,c9
for(int i=0;i<nEndPos.length-1;i++) l)E \mo 8
{ bL5z%bV
nEndPos = nStartPos[i+1]; xKKL4ws
} D3yG@lIP3
nEndPos[nEndPos.length-1] = nFileLength; {O*<1v9<
} *zX*k7LnV
} D"fE )@Q@Y
'>> IMF
%7BVJJp2
//启动子线程 e!yUA!x`u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v=?U{{xQ
for(int i=0;i<nStartPos.length;i++) MjC;)z
{ #5O'XH5_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V%&t'H{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -CW&!oW
nStartPos,nEndPos,i); ^z3-$98=A
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /E(H`;DG
fileSplitterFetch.start(); 2XrPgq'
} "Iu[)O%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $DC*&hqpt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); BM{GSX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "/hM&
nEndPos = " + nFileLength); x Yr-,$/
// fileSplitterFetch[nPos.length-1].start(); {e[S?1t=l
J) v~
_#9:cH*
//等待子线程结束 jJl6H~ "q
//int count = 0; 9BB<. p
//是否结束while循环 hi,!
boolean breakWhile = false; Y-&r_s_~
,s0E]](
%[4/UD=7
while(!bStop) i](,s.
{ Ojp)OeF\
write_nPos(); DR/qe0D
Utility.sleep(500); %a+X\\v2
breakWhile = true; G5Y5_r6Gu
o7VNw8Bp
Ea1{9>S
for(int i=0;i<nStartPos.length;i++) "+s#!Fh *
{ :7p0JGd
if(!fileSplitterFetch.bDownOver) TCp!4-~,
{ 49}yw3-
breakWhile = false; "s2?cQv{#
break; c"t1E-Nsk
} 4vTO #F
} k|-`d
if(breakWhile) PaV[{CD
break; &oiX/UaY
@Fqh]1t
rq9{m(
//count++; nL@ "FZ`(
//if(count>4) hC<X\yxe
// siteStop(); 'P}"ZHW
} FCQoz"M
W^0F(9~!(
m_~ p G
System.err.println("文件下载结束！"); qAm$yfYs`
} l?(nkg["nY
catch(Exception e){e.printStackTrace ();} W5(t+$L.
} y4)M,+O5
X`]-)(UX
G;V@oT
//获得文件长度 BDxrSq,H
public long getFileSize() 2F^ %d9`
{ lO8.Q"mxo
int nFileLength = -1; F1R91V|
try{ 5/DTE:M<
URL url = new URL(siteInfoBean.getSSiteURL()); k);z}`7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Dqe)8 r
httpConnection.setRequestProperty("User-Agent","NetFox"); ?LgR8/Io@5
Gk,{{:M:5
MLY19;e
int responseCode=httpConnection.getResponseCode(); M$-4.+G
if(responseCode>=400) hxx,E>k
{ _`/0/69
processErrorCode(responseCode); O+`^]D7
return -2; //-2 represent access is error #`:s:bwM:
} 2ko7t9y&
tu77Sb
+-'qI_xo
String sHeader; E xKH%I
nFW^^v<
vX)6N#D!
for(int i=1;;i++) MjE.pb
{ EG&^;uU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n=r}jRH1
//Utility.log(in.readLine()); l7aGo1TcIh
sHeader=httpConnection.getHeaderFieldKey(i); Xn"n5=M
if(sHeader!=null) m0]LY-t
{ swG^L$r`
if(sHeader.equals("Content-Length")) 4DEsB)%X
{ v6oPAqj,r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); riZFcVsB
break; G6JyAC9j
} VbM5]UT/
} /}2 bsiJT
else 0NfO|l7P
break; zJI/j _~W
} ,.]e~O4R
} Y:^ =jV7
catch(IOException e){e.printStackTrace ();} !W^2?pqN
catch(Exception e){e.printStackTrace ();} X~0l1 @!
kR^7Z7+#*
Y@KZ:0<
Utility.log(nFileLength); nX5*pTfjL3
pW:h\}%`n
jCW>=1:JGY
return nFileLength; (&PamsV*8
} 'nP'MA9b;a
PZNo.0M70
vbqI$F[s
//保存下载信息（文件指针位置） w?C_LP
private void write_nPos() )g:UH Ns
{ [2 2IF
try{ MP[v 9m@
output = new DataOutputStream(new FileOutputStream(tmpFile)); \*LMc69
output.writeInt(nStartPos.length); n8[sR;r5f
for(int i=0;i<nStartPos.length;i++) x@DXW(
{ sl6p/\_w
// output.writeLong(nPos); {,IWjt &>
output.writeLong(fileSplitterFetch.nStartPos); ?MKf=!w
output.writeLong(fileSplitterFetch.nEndPos); P)1@HDN==
} \q3H#1A
output.close(); tyP-J4J
} f*XF"@ZQV
catch(IOException e){e.printStackTrace ();} \2_>$:UoV
catch(Exception e){e.printStackTrace ();} edGV[=]F
} Ez?vJDd
:FG}k Y
Q)#<T]~=
//读取保存的下载信息（文件指针位置） oCy52Bm.!
private void read_nPos() HZ8 j[kO
{ UgJlXB|a%2
try{ <kLY1EILM
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8S]Mf*~S'
int nCount = input.readInt(); 6;n^/3*#
nStartPos = new long[nCount]; L!S-f4^5
nEndPos = new long[nCount]; yel>-=Vn
for(int i=0;i<nStartPos.length;i++) d/Py,
{ ,EZ&n[%Ko
nStartPos = input.readLong(); %T'?7^\>
nEndPos = input.readLong(); 4Xz6JJ1U[H
} 1"/V?ArfL
input.close(); + A0@#:B
} qu[w_1%S
catch(IOException e){e.printStackTrace ();} !Q.c8GRUQ
catch(Exception e){e.printStackTrace ();} V.y+u7<3}
} W3<O+S&
KNY<"b
0p2 0Rt
private void processErrorCode(int nErrorCode) zNE!m:s
{ yqejd_cd
System.err.println("Error Code : " + nErrorCode); 'Dat.@j
} =7e8N&-nv
^]U2Jd
!-N!80
//停止文件下载 "3\RJ?eW:S
public void siteStop() 7e8hnTzl8<
{ K"}Dbr
bStop = true; jQb=N%5s
for(int i=0;i<nStartPos.length;i++) cYbO)?mC_
fileSplitterFetch.splitterStop(); +D h=D*
I]k'0LG*^
<ht>>
} :[ITjkhde0
} rA1 gH6D
//负责部分文件的抓取 8OBvC\%
**FileSplitterFetch.java MO _9Yi
*/ 8z/^Ql
package NetFox; d\)v62P
2Cr+Z(f
W!X#:UM)
import java.io.*; cU{LyZp
import java.net.*; r#Pd@SV
8U;!1!+ 7)
{;p/V\
public class FileSplitterFetch extends Thread { z9D2,N.
(XW#,=rYk
Fn[~5/
String sURL; //File URL qb"!
long nStartPos; //File Snippet Start Position `Mjm/9+18
long nEndPos; //File Snippet End Position Rp@u.C<
int nThreadID; //Thread's ID htF&VeIte
boolean bDownOver = false; //Downing is over (vI7qD_
boolean bStop = false; //Stop identical Ce0I8B2y
FileAccessI fileAccessI = null; //File Access interface wz, \zh
wR;l"*j
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException EXBfzK)a
{ vaQ,l6z .h
this.sURL = sURL; M}nalr+#
this.nStartPos = nStart; s]I],>}RU
this.nEndPos = nEnd; F;b|A`M
nThreadID = id; mdZELRu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qnA:[H;F
} B"qG-ci
5=?&q 'i
<;XJ::d
public void run() ]!A;-m
{ K[ \z'9Q
while(nStartPos < nEndPos && !bStop) CD[7h
{ #ERn 8k
fk"{G>&8
:?p{ga9
try{ +]>a`~
URL url = new URL(sURL); .H>Rqikj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S5d{dTPq
httpConnection.setRequestProperty("User-Agent","NetFox"); q6ikJ8E8b
String sProperty = "bytes="+nStartPos+"-"; "~[Rwh?
httpConnection.setRequestProperty("RANGE",sProperty); - a=yid
Utility.log(sProperty); t]` 2f3UO
q@\_q!
sbs"26IE
InputStream input = httpConnection.getInputStream(); .U1dcL6
//logResponseHead(httpConnection); Y{O&-5H^|
ex|kD*=
b9YpUm7#
byte[] b = new byte[1024]; +p[~hM6?
int nRead; gO/(/e>P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JxvwquI
{ =3T?U_u@
nStartPos += fileAccessI.write(b,0,nRead); }+lxja]C
//if(nThreadID == 1) H,I}R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :D,YR(])
} ew"Fr1UGYZ
lvN{R{7>
oby*.61?5l
Utility.log("Thread " + nThreadID + " is over!"); ;?[~]"
bDownOver = true; {jVFlKP>
//nPos = fileAccessI.write (b,0,nRead); \8$`:3,@
} OM.^>=
catch(Exception e){e.printStackTrace ();} =;`YtOL
} w %zw+E
} 6,7omYof
U=t'>;(g
VsmL#@E
//打印回应的头信息 +sI.GWQ_:
public void logResponseHead(HttpURLConnection con) a(7ryl~c=
{ xC{NIOYn'
for(int i=1;;i++) ~3%3{aa
{ _kd |:,
String header=con.getHeaderFieldKey(i); Z\L@5.*ydE
if(header!=null) _qg6( X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %b?Pasf.
Utility.log(header+" : "+con.getHeaderField(header)); &-*nr/xT
else k|_2aQ02
break; |. 6@-h~8
} (LfVa`<1
} f8 jaMn9o
Y;w]u_
}-vBRY
public void splitterStop() y(dS1.5F
{ Z~uKT n
bStop = true; br;G5^j3?
} ]M2<I#hF.
./ :86@O
]/bE${W*]
} i#lo?\PO>
ypd?mw&1}
4yA`);r62
/* g@2.A;N0
**FileAccess.java Z]Y4NO;
*//文件访问(定位，写) ]Rye AJ3
package NetFox; AAW7@\q.
import java.io.*; 6:,^CI|@t
2{CSH_"Z7
V\"5<>+O
public class FileAccessI implements Serializable{ hkJZqUA
vo$66A
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /4?`F}7)
RandomAccessFile oSavedFile; ]cr;PRyv
long nPos; W,~1KUTc
s2v*
b8>9mKs
public FileAccessI() throws IOException ddP,_.0
{ h7$!wf!I
this("",0); ^{s0d+@{
} ~Z2eQx jtM
PR?clg=z
:#}`uR,D/
public FileAccessI(String sName,long nPos) throws IOException [S:)UvB
{ {*U:Wm<
oSavedFile = new RandomAccessFile(sName,"rw"); cnthtv+(~
this.nPos = nPos; 9ojhI=:
oSavedFile.seek(nPos); gcxk'd
} sQZ8<DpB
f>dkT'4
,7P^]V1
public synchronized int write(byte[] b,int nStart,int nLen) !P$xh
{ \2pFFVT
int n = -1; A232"p_
try{ E5 oD|'=WA
oSavedFile.write(b,nStart,nLen); jyhzLu
n = nLen; / yi:Q0
} a1SOC=.M;
catch(IOException e) BUinzW z{a
{ mj=|oIMwT
e.printStackTrace (); 'cN#rHPB6
} }yw;L(3
%,et$1`g
.,Qnn}:l
return n; ^gzNP#A<'o
} "PaGDhS
fR4l4 GU?)
M7R&J'SAY
} t3$gwO$
JF%=Bc$C
3|Sy'J0'K
/* C-u/{CP
**SiteInfoBean.java Ok&>[qu
*/ HY;?z`=
package NetFox; %uVJLz
Lc<xgN+cJ
i8_x1=A
public class SiteInfoBean { U!:!]DX(
oxQID
%:KV2GP
private String sSiteURL; //Site's URL vQmackY
private String sFilePath; //Saved File's Path !`[I>:Ex
private String sFileName; //Saved File's Name 8 QF?W{NK
private int nSplitter; //Count of Splited Downloading File \.P}`Bpa
I<./(X[H:#
^r*%BUU9]%
public SiteInfoBean() o?K|[gNi
{//nSplitter的缺省值为5 6bKO;^0
//default value of nSplitter is 5 DhNo +"!z
this("","","",5); Sn2Ds)Pfx3
} qMES<UL>
>B/&V|E
jne9=Als5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) t!~YO'<dS
{ ^>8]3@ Nh
sSiteURL= sURL; &17,]#3
sFilePath = sPath; ynZ[c8.
sFileName = sName; |sqo+E
this.nSplitter = nSpiltter; ?lDcaI>+n
}<ONxg6Kb
l$VxE'&LQ
} w2N3+Tkg
>xV<nLf/
&rztC]jF
public String getSSiteURL() R P:F<`DB|
{ ]Wd`GI
return sSiteURL; yC0f/O
} $dTfvd
9id~NNr7
o1X/<.0+
public void setSSiteURL(String value) GGc_9?h
{ "Dl9<EZ
sSiteURL = value; ?ey&Un"
} 6!%d-Z7)
b^,Mw8KsO
x)VIA]
public String getSFilePath() ;5Vk01R
{ +yb$[E*
return sFilePath; f'6qJk%J
} Uk*;C
R^yZG{?t
_d[2_b1
public void setSFilePath(String value) LlA`QLe
{ rw8J:?0x
sFilePath = value; nN=:#4 >Y
} pO/SV6N
vbA7I<;
A2|o=mOH
public String getSFileName() \gp,Txueb
{ AO}i@YJth
return sFileName; _Hd1sx
} <a+eF}*2
9VUm=Z#`
}.MoDR3\
public void setSFileName(String value) oBj>9I;
{ c7g.|R
sFileName = value; X4}`>
} 1R2o6`_
/%uZKGP
c. TB8Ol
public int getNSplitter() /;<e.
{ _7=pw5[
return nSplitter; iVKbGgA
} QypiF*fSU
"6E1W,|{
loeLj4""
public void setNSplitter(int nCount) _)#=>$k\
{ O,=Q1*c,&
nSplitter = nCount; =tS[&6/
} TDl!qp @
} !#c[~erNZ
lbKv
Tw`c6^%^y
/* iM/*&O}
**Utility.java oDW<e'Jm
*/ I(^jOgYU
package NetFox; d4p{5F7]^
^A11h6I
u+z .J4w
public class Utility { Ufaqhh
q!hy;K`Jd
''(fH$pY
public Utility() v?YdLR
{ e7XsyL'|p
eg$5z Z
{{.sEi*
} Y( 1L>4
V#gF*]q
//线程睡眠 6bbZ<E5At
public static void sleep(int nSecond) ,5eH2W
{ ;&+[W(7Sy
try{ Sv~YFS :oy
Thread.sleep(nSecond); @ate49W
} <+? Y
catch(Exception e) 2fkIdy#n@
{ ~T>jBYI0
e.printStackTrace (); (#j2P0B
} Gut J_2f^9
} {?EEIfg
VY+(,\)U
//日志 \~gA+o}Q
public static void log(String sMsg) NJ|NJp&0
{ H _Zo@y~J
System.err.println(sMsg); 'a;ini
} ( }]37
,J~,ga~
wJ80};!
public static void log(int sMsg) vQ-ixh
{ 93Mdp9v+i
System.err.println(sMsg); ^%n124
} n_""M:XH
} !lQ#sL`
F5N>Uqr*oN
v!<PDw2'
/* hmK8jl<6
**TestMethod.java j+_S$T8w
*/ \6`v.B&v
package NetFox; 2 ) TG
$ZQlIJZ
6QN1+MwB
public class TestMethod { GB&Nt{
4R&*&GZ#
l `fW{lh
public TestMethod() 8A2if9E3
{ ///xx/weblogic60b2_win.exe w1wXTt
try{ k~0#'I9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \We"?1^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 98ca[.ui
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6#E]zmXO2
fileFetch.start(); K#GXpj
} |7rR99
catch(Exception e){e.printStackTrace ();} P['X<Xt8
IXGW2z;
[ 3$.*
} tO?21?AD D
7*zB*"B'1t
qTyg~]e9(
public static void main(String[] args) KK:N [x
{ u$WBc\j
new TestMethod(); CnabD{uTf
} oJP<'l1
} ?Wwh _TO
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