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)); ?yt"
} mam2]St"
for(int i=0;i<nEndPos.length-1;i++) "J%/xj
{ 3EKqXXzOB
nEndPos = nStartPos[i+1]; 38T2IN
} cB9`U4<
nEndPos[nEndPos.length-1] = nFileLength; YkLEK|d
} O)!MWmr
} Ym*Ed[S
u%=M4|7
rTjV/~
//启动子线程 G#;$;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZO $}m?
for(int i=0;i<nStartPos.length;i++) t`X-jr)g
{ lvz&7Zb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7:t *&$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e'uI~%$NJL
nStartPos,nEndPos,i); ?gMxGH:B.&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v='h
fileSplitterFetch.start(); 4#m"t?6!
} ;F;`y),
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \^+=vO;A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )5U&^tJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T=w5FT
nEndPos = " + nFileLength); EV 8}C=
// fileSplitterFetch[nPos.length-1].start(); D-BWgK
^w XXx=Xf
)Aky:kM$
//等待子线程结束 L{\au5-4
//int count = 0; jnuovM!x~
//是否结束while循环 6A]Ia4PL
boolean breakWhile = false; :8bz+3p
sCFqz[I
8L<GAe
while(!bStop) zl j%v/9
{ it~>)_7*P
write_nPos(); `}^_>
Utility.sleep(500); 9ci=]C5o3K
breakWhile = true; "$tP>PO{<
L;0ZB=3n
X|F([,o
for(int i=0;i<nStartPos.length;i++) 'o2x7~C@
{ bqxbOQd
if(!fileSplitterFetch.bDownOver) p`3pRrER
{ }w&+H28.#
breakWhile = false; el*C8TWlw
break; 37@_"
} Q2)z1'Wv
} i!30f^9D-S
if(breakWhile) :*"0o{ ie
break; A({8p
nJ`JF5tI
&zr..i4O
//count++; UNJ]$x0
//if(count>4) x62b=k}
// siteStop(); MeqW/!72$L
} Fa$ pr`
qsUlfv9L6
eXI^9uH
System.err.println("文件下载结束！"); 2c.~cNx`q[
} HPGi5rU
catch(Exception e){e.printStackTrace ();} XTD_q
} )x-iru A:
BOLG#}sm
MmBM\Dnv
//获得文件长度 ?3"bu$@8
public long getFileSize() N&!qur \
{ [{ak&{R,9{
int nFileLength = -1; :cmfy6h]
try{ is%qG?,P
URL url = new URL(siteInfoBean.getSSiteURL()); +%G*)8N3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *K6 V$_{S
httpConnection.setRequestProperty("User-Agent","NetFox"); C G~)`
] }XK
?]081l7cd
int responseCode=httpConnection.getResponseCode(); cjf}yn
if(responseCode>=400) #_}lF<k
{ ,>n 4 `A
processErrorCode(responseCode); -Rhxib|<
return -2; //-2 represent access is error xQC.ap
} twqjaFA>
+d6/*}ht
ul+ +h4N
String sHeader; &E$jAqc
IBY3QG
%b2.JGBqJ
for(int i=1;;i++) '2a}1?
{ FS r`Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xi_>hL+R(
//Utility.log(in.readLine()); Zr_{Z@IpU
sHeader=httpConnection.getHeaderFieldKey(i); pJx88LfR
if(sHeader!=null) \BaN?u)a
{ '|<+QAc
if(sHeader.equals("Content-Length")) |C@)#.nm[
{ ho2o/>Ef3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z.$ncP0s
break; %O;"Z`I
} \pB"R$YZ6
} GWgjbp
else LWc}j`Wd
break; oYnA 3
} Aj.TX%}`h
} 8zGe5Dn9
catch(IOException e){e.printStackTrace ();} EXg\a#4['
catch(Exception e){e.printStackTrace ();} X%xX3e'
; )O)\__"-
B=#rp*vwL
Utility.log(nFileLength); X3I\O,"I
T5&jpP`M
Eu\&}n`i
return nFileLength; @#1k+tSA,
} )H#Hs<)Qy
f.rz2)o
;RW!l pGjP
//保存下载信息（文件指针位置） Mi9A%ZmP
private void write_nPos() bV&/)eqv
{ (F]f{8
try{ /s(/6~D|
output = new DataOutputStream(new FileOutputStream(tmpFile)); ox] LlRK
output.writeInt(nStartPos.length); |uQJMf[L)
for(int i=0;i<nStartPos.length;i++) qr$=oCqa
{ Yva^JB
// output.writeLong(nPos); 3'O+
output.writeLong(fileSplitterFetch.nStartPos); 5[esW
output.writeLong(fileSplitterFetch.nEndPos); !zwnFdp
} m;lwMrY\7>
output.close(); U;:>vi3p
} 07Yh
catch(IOException e){e.printStackTrace ();} |]HU$GtS
catch(Exception e){e.printStackTrace ();} |:`f#H
} BKIAc6
x SF#ys4v
eP|:b &
//读取保存的下载信息（文件指针位置） FD*`$.e3\
private void read_nPos() >IC.Zt@
{ *j2P#et
try{ EYd`qk3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +?[TH?2c+
int nCount = input.readInt(); xaX3<V@S
nStartPos = new long[nCount]; $.(%7[
nEndPos = new long[nCount]; }]N7CWy
for(int i=0;i<nStartPos.length;i++) 7qV_QZ!.
{ bqN({p&
nStartPos = input.readLong(); xIf,1g@Cq9
nEndPos = input.readLong(); 1[C,*\X8v
} Z_D8}$!
input.close(); ~K 8eRT
} .JZoZ.FAb
catch(IOException e){e.printStackTrace ();} %+ig7a:
catch(Exception e){e.printStackTrace ();} ..3TB=Z#
} #IA[erf:
CtV$lXxup
NwoBM6 #
private void processErrorCode(int nErrorCode) ++F #Z(p
{ 7m{ 'V`F
System.err.println("Error Code : " + nErrorCode); 2[LT!TT
} [#$-kd~
"3LOL/7f
Xz4!#,z/
//停止文件下载 W*e6F?G
public void siteStop() ooreforr
{ U")~bU
bStop = true; N?U;G*G
for(int i=0;i<nStartPos.length;i++) 4~hd{8
fileSplitterFetch.splitterStop(); D)8&v`LS
a9mLPP
I1BVqIt1i
} NZ/gp"D?
} YTpSR~!Rj
//负责部分文件的抓取 G$}\~dD
**FileSplitterFetch.java JGX E{FT
*/ _W/s=pCh
package NetFox; fySzZ
hf^,
Y[i>
import java.io.*; m,,-rC
import java.net.*; |3/=dG
YH&`+ +
f%` =>l
public class FileSplitterFetch extends Thread { b/5?)!I
j1*'yvGM
kq8:h
String sURL; //File URL $IA(QC_]AO
long nStartPos; //File Snippet Start Position Oj\lg2Ck
long nEndPos; //File Snippet End Position HhhN8t
int nThreadID; //Thread's ID D'ZR>@w@
boolean bDownOver = false; //Downing is over hU3c;6]3
boolean bStop = false; //Stop identical L&MR%5
FileAccessI fileAccessI = null; //File Access interface WW\u}z.QJ
=LDzZ:' X
g2JNa?z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [U]U *x
{ \Pi\c~)Pr
this.sURL = sURL; 9Iq[@v
this.nStartPos = nStart; *r@7:a5
this.nEndPos = nEnd; b4ZZyw
nThreadID = id; QxH%4 )?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R22YKXU
} 7/a[;`i*!
S3EY9:^C
_?M34&.X
public void run() tisSj?+
{ P{i\x#
while(nStartPos < nEndPos && !bStop) M' e<\wqm
{ m.pB]yq&
jB!p,fqcb
I;<0v@
try{ ~ P"@^cq
URL url = new URL(sURL); 6O bB/*h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u\ro9l
httpConnection.setRequestProperty("User-Agent","NetFox"); $~!%Px)
String sProperty = "bytes="+nStartPos+"-"; R2vT\ 6xv
httpConnection.setRequestProperty("RANGE",sProperty); BCYTlxC'
Utility.log(sProperty); %i{Z@
U<gMgA
@)1>ba
InputStream input = httpConnection.getInputStream(); zflfV!vAg
//logResponseHead(httpConnection); Gole7I
&l"/G%W
jzI70+E
byte[] b = new byte[1024]; >!848J
int nRead; rn $a)^!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7DDd1"jE
{ ?;zu>4f|
nStartPos += fileAccessI.write(b,0,nRead); a\>+!Vq
//if(nThreadID == 1) n/6#rj^$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NY 756B*
} Atc9[<~WG
<K;
C]414Ibi
Utility.log("Thread " + nThreadID + " is over!"); %V71W3>6WS
bDownOver = true; !TvNT}4Z
//nPos = fileAccessI.write (b,0,nRead); FM;NA{
} _8A
catch(Exception e){e.printStackTrace ();} g"ha1<y<
} r*HbglB
} #%N v\g;
p4GhT~)l:
cWjb149@)
//打印回应的头信息 0gO_dyB
public void logResponseHead(HttpURLConnection con) mivb}cKM
{ <}t~^E,
for(int i=1;;i++) 39to5s,
{ "5 ;fuM1
String header=con.getHeaderFieldKey(i); U;`C%vHff
if(header!=null) J|,Uu^7`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V[ju7\>$Z
Utility.log(header+" : "+con.getHeaderField(header)); 86Hg?!<i.
else uP, iGA
break; })W9=xO~
} <|Srbs+
} 7]W6\Z
(rqc_ZU5
7OAM
public void splitterStop() 'L?e)u.
{ fh_+M"Y0`
bStop = true; -!;2?6R9{
} ;\j7jz^uC
zU7co.G
Ha~F&H|"O
} _D~l2M
K&ZN!VN/p
} I>68dS[
/* !C\$=\$
**FileAccess.java 9d&@;&al
*//文件访问(定位，写) ^POHQQ
package NetFox; V%h,JA
import java.io.*; p0*qv"lA
2[|52+zhc
`#HtVI
public class FileAccessI implements Serializable{ +t*V7nW
j9gn7LS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i(T[
RandomAccessFile oSavedFile; `-t8ag3
long nPos; !LI6_Oq
JfD-CoQS'
fg$#ZCi
public FileAccessI() throws IOException fi%)520
{ &1/OwTI4J
this("",0); WC0z'N({W
} Kb X&E0
-t]3 gCLb
lXtsnQOOK
public FileAccessI(String sName,long nPos) throws IOException riR(CJ}Ff
{ LMKhtOZ?
oSavedFile = new RandomAccessFile(sName,"rw"); $UNC0(4
this.nPos = nPos; mtU{d^B
oSavedFile.seek(nPos); {zX]41T
} Fn>KdoByN
)<Fq}Q86
4)"S/u
public synchronized int write(byte[] b,int nStart,int nLen) dG&^M".(
{ >{6U1ft):
int n = -1; UQZl:DYa
try{ [Ef6@
oSavedFile.write(b,nStart,nLen); QB uX#bDV
n = nLen; 5(zdM)Y7
} Q XSS
catch(IOException e) |I[/Fl:
{ "; 1@f"kw
e.printStackTrace (); P~ : N
} d1P|v( `S9
Qb%o%z?hee
(+yH
return n; 3rVfBz
} (E;+E\E
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*+OS;R1<
} uMx6:
!"2S'oQKS
OZc4 -5
/* }y%c.
**SiteInfoBean.java CvHE7H|-{
*/ fmq''1u
package NetFox; K| dI'TnW
44NMof8N
Gv[s86AP,
public class SiteInfoBean { 1=Z!ZY}}e
3Ccy %;
InI>So%e|<
private String sSiteURL; //Site's URL 3v@h&7<E
private String sFilePath; //Saved File's Path }u9#S
private String sFileName; //Saved File's Name ?g\emhG
private int nSplitter; //Count of Splited Downloading File Nq9\2p
m"@o
nU4to
public SiteInfoBean() 3k3C\Cw
{//nSplitter的缺省值为5 xa.tH)R
//default value of nSplitter is 5 Ul_5"3ze
this("","","",5); #M%K82"
} TZ63=m
JM1O7I
V408uy-M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :8K}e]!c1
{ ?K+q~DzNSD
sSiteURL= sURL; ~NZL~p
sFilePath = sPath; ;j.-6#n
sFileName = sName; F\, vIS
this.nSplitter = nSpiltter; [~PR\qm
Ur]/kij
o%bf7)~s
} |1GOm=GNK
6Df*wi!jI
,<N{Y[n]e
public String getSSiteURL() HfZ^ED"}
{ 0 N"N$f
return sSiteURL; 'W,*mfB
} IyI0|&r2A
q{&\nCy
0-~s0R89A
public void setSSiteURL(String value) =A!rZG
{ ta6>St7.
sSiteURL = value; l\F71pwSI
} V@g v
[YP{%1*RM
[GPCd@
public String getSFilePath() y XKddD
{ s`ZP2"`f
return sFilePath; $*VZa3B\
} 06O_!"GD}
|h}4J
\-pqqSy
public void setSFilePath(String value) 3dSb!q0&N
{ ,]:Gn5~
sFilePath = value; ~`Rar2%B
} ?JG^GD7D
D2g/P8.<A
d<+hQ\BF,
public String getSFileName() GGnlkp& E
{ /o%VjP"<
return sFileName; obE8iG@H
} }zks@7kf
Unv'm5/L
L2+cVR
public void setSFileName(String value) y>.t[*zT
{ ;DSH$'1i
sFileName = value; aZ$5"
} Y0.'u{J*
S2DG=hi`GK
67hfve
public int getNSplitter() gROK4'j6y
{ 0^R, d M
return nSplitter; zz[fkH3
} %YK xdp
ywl=@
#bBh. ^
public void setNSplitter(int nCount) UOsK(mB
{ #M{qMJHDo
nSplitter = nCount; ,#FP]$FK
} gyD;kn\CP
} i(pHJP:a:
2,dWD<h
T\n6^@.>
/* E_En"r)y
**Utility.java S :8
*/ 70GBf"
package NetFox; 'AX5V-t
8 eK8-R$
$&&E[JY
public class Utility { 2mnAL#
^P^%Q)QXl
e*qGrg(E
public Utility() M,S'4Szuk
{ $%q=tn'EX
nX 9]dz
(5 @H
} w6Nnx5Ay
y/y~<-|<@
//线程睡眠 qxb]UV,R
public static void sleep(int nSecond) oWL_Hh%-f`
{ u1L^INo/
try{ }rI:pp^KS
Thread.sleep(nSecond); p09p/
} 'Gqv`rq&
catch(Exception e) ;RJ 8h x
{ 7dcR@v`c
e.printStackTrace (); 3PGAUQR#"q
} _<LL@IX
} @U18Dj[
A $gn{ c
//日志 8'zZVX D<
public static void log(String sMsg) y7M{L8{0
{ z,4mg6gt
System.err.println(sMsg); '{UKO7
} ] re=8s6
E#!!tH`lgg
Cp(2]Eb
public static void log(int sMsg) Nw'03Jzx_
{ '"fJA/O
System.err.println(sMsg); q6)fP4MQ]
} kFwFPK%B
} E{&MmrlL,
.a]#AFX
-1,0hmn=+
/* /V:9*C
**TestMethod.java [K.1 X=O}
*/ Q}|K29Y:p
package NetFox; 3y6\0|{1
8rH6L:]S
8{!d'Pks
public class TestMethod { 3{$7tck,
N o6!gZ1
d]]z )
public TestMethod() ![^pAEgx
{ ///xx/weblogic60b2_win.exe YND}P9 h
try{ )Q'E^[Ua
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g w([08
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NC%hsg^0/
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4}h}`KZZ
fileFetch.start(); yl~_~<s6
} WJOoDS!i
catch(Exception e){e.printStackTrace ();} (MI>7| ';
\4q|Qno8
qK a}O*
} GYfOwV!zB
80*hi)ux[
b&+zAt.
public static void main(String[] args) \~l_w ,Poo
{ `SFeln{1B
new TestMethod(); <ToBVGX
} Lj3o-@\*j
} hc3hU
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