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)); HKu? J
} fZ8%Z
for(int i=0;i<nEndPos.length-1;i++) ' >a(|
{ { FVLH:{U^
nEndPos = nStartPos[i+1]; }diB
} n0|oV(0FE
nEndPos[nEndPos.length-1] = nFileLength; \Tf[% Kt x
} _dOR-<
} fik*-$V`
GIXxOea1
1k-YeQNe
//启动子线程 VB 53n'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <T]BSQk
for(int i=0;i<nStartPos.length;i++) ZlaU+Y(_[
{ 7ux0|l
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {OFbU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cp D=9k!*K
nStartPos,nEndPos,i); 0($@9k4!/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \@G 7Kk*l
fileSplitterFetch.start(); X!=E1TL
} )P&>Tc?;z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @JJ,$?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hcWYz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #4hxbRN
nEndPos = " + nFileLength); tA#7Xr+
// fileSplitterFetch[nPos.length-1].start(); :cDhqBMNr`
n~~0iU)
mqw5\7s?
//等待子线程结束 ^{z@=o<o
//int count = 0; ]O%wZIp\P
//是否结束while循环 E=N44[`.G
boolean breakWhile = false; $P<T`3Jg
b| e7mis@
yGGQ;!/
while(!bStop) K@uUe3
{ {+D 6o
write_nPos(); E?$|`<o{|`
Utility.sleep(500); %:61@<
breakWhile = true; tE&@U$0>o
""AP-7
BS-nny
for(int i=0;i<nStartPos.length;i++) w[`2t{^j
{ Po+I!TL'
if(!fileSplitterFetch.bDownOver) #<_gY
{ sK1YmB :~a
breakWhile = false; 5Q_T=TL
break; QGv$~A[h
} D,cGW,2Nv
} Kob i!
if(breakWhile) Af*e:}}
break; rByC6HV"
-e#~CE-
pwj?
//count++; w5j6RQml
//if(count>4) *g0}pD;r
// siteStop(); %V40I{1
} a4'KiA2r
_hM #*?}v
wUUDq?!k\
System.err.println("文件下载结束！"); $bf&ct*$h
} )C?bb$ G
catch(Exception e){e.printStackTrace ();} $e(]L(o;
} jg2UX
cvoE4&m!
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//获得文件长度 px|y_.DB2x
public long getFileSize() 6??o(ziK$
{ d4y?2p ?3
int nFileLength = -1; 5U%J,W
try{ b=V"$(Q
URL url = new URL(siteInfoBean.getSSiteURL()); ,7` /D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !Q-h#']~L
httpConnection.setRequestProperty("User-Agent","NetFox"); &ZkY9XO
JCL+uEX4S
h6Femis
int responseCode=httpConnection.getResponseCode(); /(/Z~J[
if(responseCode>=400) d!BQ%a
{ C!]R0L*
processErrorCode(responseCode); .Vohd@s9l
return -2; //-2 represent access is error "nkj_pC
} 0Dx,)C
(#|CL/&
z]/;?
String sHeader; j41)X'MgJ
M4%u~Z:4h+
uc0 1{t0,
for(int i=1;;i++) bfjC:"!H
{ s& INcjC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X#625h
//Utility.log(in.readLine()); 7(ni_|$|
sHeader=httpConnection.getHeaderFieldKey(i); [w0@7p"7
if(sHeader!=null) ,r=9$i_
{ Iq76JJuCb
if(sHeader.equals("Content-Length")) hW^*b:v{
{ YY!Lv:.7>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [r[IWy(}
break; .f1
} }OQaQf9V{
} sj;n1t}$S
else Qs38VlR_m
break; tl:V8sYTP
} d|P,e;m-
} _*tU.x|DP
catch(IOException e){e.printStackTrace ();} K-_XdJ\
catch(Exception e){e.printStackTrace ();} 74[wZDW|(
SJseP_-
e(e_p#
Utility.log(nFileLength); x.5!F2$
LB(I^
JEw+5MO@
return nFileLength; 4tQ~Z6Jn;
} J$aE:g6'
SG5GJCkc
-qI8zs$:5
//保存下载信息（文件指针位置） 4AIo,{(
private void write_nPos() 5%qq#;[n
{ X.q,
try{ TFfV?rBI
output = new DataOutputStream(new FileOutputStream(tmpFile)); cO8':P5Q
output.writeInt(nStartPos.length); :.k1="H~@
for(int i=0;i<nStartPos.length;i++) {V8yJ{.G
{ 3"*tP+H
// output.writeLong(nPos); fbTq?4&Q
output.writeLong(fileSplitterFetch.nStartPos); )S:,q3gxJ
output.writeLong(fileSplitterFetch.nEndPos); eD(;Wn
} bv&#ay7
output.close(); O/(QLgUr
} :V9%R~h/
catch(IOException e){e.printStackTrace ();} D(E3{\*R
catch(Exception e){e.printStackTrace ();} ~pZ<VH;h
} _/Sqw
'-,$@l#
^"\3dfzKM
//读取保存的下载信息（文件指针位置） 0[# zn
private void read_nPos() _#dBcEH[
{ s%&/Zt
try{ VW$a(G_h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Gu#Vc.e
int nCount = input.readInt(); O(R1D/A[
nStartPos = new long[nCount]; TR<M3,RG#%
nEndPos = new long[nCount]; G!u+~{g
for(int i=0;i<nStartPos.length;i++) {Vw\#/,
{ 46^9O 5J
nStartPos = input.readLong(); >U~{WM$"Y
nEndPos = input.readLong(); `{Jo>L.
} a-cLy*W,~
input.close(); Lhts4D/V7
} rIh"MQvi[
catch(IOException e){e.printStackTrace ();} g3Xab
catch(Exception e){e.printStackTrace ();} PeX^aEc
} H|.cD)&eYy
&'V1p4'
|]Eli%mNe
private void processErrorCode(int nErrorCode) F3?PlH:Y
{ kS7`g A
System.err.println("Error Code : " + nErrorCode); QX`T-)T e
} nxjP4d>
TQ,KPf$0U
Ah?,9r=U
//停止文件下载 ^t$xR_
public void siteStop() @^2?97i c
{ O x),jc[/
bStop = true; =d*5TyAcu
for(int i=0;i<nStartPos.length;i++) t=;P1d?E;
fileSplitterFetch.splitterStop(); 8ofKj:W]
rjo1
G%HuB5:u
} hr/H vB
} 0|}]=XN^
//负责部分文件的抓取 W"v"mjYud
**FileSplitterFetch.java z@8W
*/ +_T`tmQ
package NetFox; lz [s
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}eK.\_t=
import java.io.*; 8Y,imj\(v
import java.net.*; xU!eT'Y
0! W$Cz[
mm:g9j
public class FileSplitterFetch extends Thread { ;ztt*py
W^k|*Y|
*}P=7TuS
String sURL; //File URL 3FgTM(
long nStartPos; //File Snippet Start Position CX}==0od
long nEndPos; //File Snippet End Position fP KFU
int nThreadID; //Thread's ID bzWWW^kNL
boolean bDownOver = false; //Downing is over aGml!N5'
boolean bStop = false; //Stop identical Pm/Rc
FileAccessI fileAccessI = null; //File Access interface u85dG7
cuoZ:Wh
'* eeup
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b6?&h:{k
{ K(3_1*e
this.sURL = sURL; )j+G4
this.nStartPos = nStart; | zyO;
this.nEndPos = nEnd; JC.nfxG@:
nThreadID = id; f.G"[p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Js'j}w
} tJvs ?eZ)
#/0d
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public void run() KK';ho,W
{ O63:t$Yx#
while(nStartPos < nEndPos && !bStop) m>9j dsqB
{ 9SQcChG~j
fZgEJsr
P^57a?[`
try{ ' 4.T1i,
URL url = new URL(sURL); tyU'[LF?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?p'DgL{
httpConnection.setRequestProperty("User-Agent","NetFox"); w(oi6kg
String sProperty = "bytes="+nStartPos+"-"; mXOY,g2w
httpConnection.setRequestProperty("RANGE",sProperty); U}R(
Utility.log(sProperty); K"/3/`T
+GvPJI
x(+H1D\W
InputStream input = httpConnection.getInputStream(); XI\P#"
//logResponseHead(httpConnection); >e^^YR^
DS|q(O=7~t
OsV'&@+G>
byte[] b = new byte[1024]; Y[rRz6.*(
int nRead; FaLc*CU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s4[PwD
{ <lgX=wx L
nStartPos += fileAccessI.write(b,0,nRead); vLs*}+f
//if(nThreadID == 1) n09P!],Xa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [ 0z-X7=e
} )?;+<,
dT7!+)s5-
-oT3`d3
Utility.log("Thread " + nThreadID + " is over!"); 2C AR2V|
bDownOver = true; .$ X|96~$
//nPos = fileAccessI.write (b,0,nRead); FEA t6
} }u]7x:lh
catch(Exception e){e.printStackTrace ();} KP&$Sl
} a];1)zVA6
} %W^Zob
?k^~qlye
b8LA|#]i
//打印回应的头信息 -sxu7I
public void logResponseHead(HttpURLConnection con) ^Rb*mI
{ >0JCu^9
for(int i=1;;i++) ;R]~9Aan
{ k`BS{,=
String header=con.getHeaderFieldKey(i); q.bxnta"
if(header!=null) $kBcnk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <~zPt&C]V
Utility.log(header+" : "+con.getHeaderField(header)); :n,x?bM
else ?|Ey WAL
break; UaB2vuL*=
} j@R"AP}
} DN;|?oNZ
]Q#k"Je
*)L~1;7j>
public void splitterStop() gu"@*,hL
{ yRR[M@Y
bStop = true; Z~]G+(
} 'fYF1gR4
#$;}-*
Pq,iR J
} ~?:>=x
V8rS~'{\
i`5Skr:M
/* "?^#+@LV
**FileAccess.java M<r]a{Yv
*//文件访问(定位，写) Gkm{b[
package NetFox; W~FU!C?]
import java.io.*; +~"(Wooi
T037|k a{
M'VJE|+t
public class FileAccessI implements Serializable{ _UV_n!R
O1!YHo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mD%IHzbn H
RandomAccessFile oSavedFile; [Z^26/5a
long nPos; sB5@6[VDI
gs&F .n
nrR2U`
public FileAccessI() throws IOException &crR nv?
{ K >Q6
this("",0); OAaLCpRp
} Dq-[b+bm
aeDhC#h
.{-X1tJ7
public FileAccessI(String sName,long nPos) throws IOException WmkCV+thA
{ J:@yG1VIp
oSavedFile = new RandomAccessFile(sName,"rw"); %2\6.c=c
this.nPos = nPos; b94+GLU8b
oSavedFile.seek(nPos); c-"vQ>ux+
} 4K ]*bF44
$>T(31)c
;Sfe.ky@6
public synchronized int write(byte[] b,int nStart,int nLen) BIEq(/-
{ 5,+fM6^V
int n = -1; `FwE^_9d
try{ AH?[K,3
oSavedFile.write(b,nStart,nLen); KquuM ]5S
n = nLen; .Rt~d^D@
} 5uV_Pkb?8
catch(IOException e) w'9!%mr
{ 7\N }QP0"u
e.printStackTrace (); Y`3\Z6KlV
} >7r%k,`
#/5eQTBD
]WK~`-3C^
return n; egAYJK-,!
} S f6%A
z<%dWz
"ruYMSpU
} 3 2"f'{
T[<554
raZkH8
/* _5S||TuNS
**SiteInfoBean.java G7i0P j
*/ N)PkE>%X
package NetFox; 9z`72(
{yB0JL}n
]L2b|a3
public class SiteInfoBean { !MVf(y$
x.$cP
eJ6 #x$I,
private String sSiteURL; //Site's URL @urZ
private String sFilePath; //Saved File's Path N 'n0I^Y1A
private String sFileName; //Saved File's Name ^j2ve's:
private int nSplitter; //Count of Splited Downloading File 4Dy1M}7
j3H_g^
8llXpe
public SiteInfoBean() ~dzD7lG6
{//nSplitter的缺省值为5 &3J^z7kU
//default value of nSplitter is 5 )!U@:x\K
this("","","",5); B`||4*
} ex^9 l b
e*}:tH
N|%r5%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =k,?+h~
{ X,Rl&K\b"
sSiteURL= sURL; #;5Qd'
sFilePath = sPath; hk$I-
sFileName = sName; O hRf&5u$
this.nSplitter = nSpiltter; g7^|(!Y%
!D?(}nag
YQtq?&0Ct
} ]')y(_{
%YbL%i|U
a5aHv/W#P
public String getSSiteURL() 3t9CN )*
{ cucmn*o?
return sSiteURL; V7`vLs-
} sAPQbTSM
RNQq"c\
:I2,
public void setSSiteURL(String value) \B:k|Pw6~
{ We\i0zUU
sSiteURL = value; s:iBl/N}
} c`&g.s@N\
R4T@ ]l&W
bg/=P>2
public String getSFilePath() P{BW^kAdH
{ D?UURURf
return sFilePath; J"@X>n
} ';!-a]N
}p-/R'
:>Bk^"
public void setSFilePath(String value) bBV03_*
{ q#I'@Jbj
sFilePath = value; iBtG@M
} TvS<;0~K
q317~z_nl
M,X)rM}Q
public String getSFileName() }_F:]lI*R
{ GY.iCub
return sFileName; &}0QnO_mj
} [La}h2gz
D?8(n=#[
_ker,;{9C
public void setSFileName(String value) 7&/1K%x9;
{ }s:3_9mE
sFileName = value; *4LRdLMn
} O*bzp-6\
5`$!s17
XA(.O|VZ
public int getNSplitter() (:o:_U
{ b|@zjh;]A7
return nSplitter; ZHUW1:qs
} /R?[/`)f&
`rK@> -
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public void setNSplitter(int nCount) hOkn@F.
{ ,grx'to(X
nSplitter = nCount; ^^*L;b>I
} i(.V`G=
} A.@wGy4
_cC1u7U9
10.ZBfn
/* rNKeY48\
**Utility.java _~{J."q
*/ P;-.\VRu
package NetFox; 2VUN
r%WHYhD
Oo-4WqRJ
public class Utility { $tXW/
l_$>$d
0I:5}$+J?
public Utility() zUDXkG*Lv
{ Qds:*]vGS
r}sO},i
?'|GGtvm
} cHR*.
E.sZjo1
//线程睡眠 -q[x"Ha%
public static void sleep(int nSecond) mxBx?xM-
{ O!hp=`B,jf
try{ sZxTsUW
Thread.sleep(nSecond); e=p_qhBt
} 6rWq hIaI
catch(Exception e) >R_m@$`
{ \ykA7Y%
e.printStackTrace (); 6d6Dk>(V
} K7.ayM 0
} &/2+'wCp5
Y~Vc|zM^(
//日志 |pbetA4&
public static void log(String sMsg) _(~LXk^C
{ Y2tBFeWY
System.err.println(sMsg); ?u;m ],w!
} #@5VT*/7
.fhfb\$
QVkji7)ZT
public static void log(int sMsg) b<#zgf
{ SK&1l`3
System.err.println(sMsg); F(Zf=$cx
} iPY)Ew`Im
} ]dl.~;3~~
"#gS?aS
Z__fwv.X[
/* *93=}1gN
**TestMethod.java ^'du@XCf}
*/ w8jpOvj
package NetFox; P*>?/I`G
fVa z'R
k h*WpX
public class TestMethod { +4Wl
)*6
#H4<8B
public TestMethod() a5O$he
{ ///xx/weblogic60b2_win.exe 0H.bRk/P+
try{ f%1\1_^g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $;}@2U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0-aaLC~Z>
SiteFileFetch fileFetch = new SiteFileFetch(bean); #O,w{S
fileFetch.start(); !};Ll=dz
} J7oj@Or9
catch(Exception e){e.printStackTrace ();} hR:i!
_A& [rBm|
" W{rS4L
} +t1+1Zv
QmGK! H>3
l Le&q
public static void main(String[] args) l-20X{$m:
{ "X._:||8
new TestMethod(); U(x$&um(l
} y!:vX6l
} e]ST0J"
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