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)); rDpe_varA
} f?2zLE>u
for(int i=0;i<nEndPos.length-1;i++) vg+r?4Q3
{ X tJswxw`K
nEndPos = nStartPos[i+1]; }R`8h&J
} zXj>K3M
nEndPos[nEndPos.length-1] = nFileLength; =L:[cIRrT;
} <2n'}&F
} Wl,%&H2S<
I'x$,s
*}+R{
//启动子线程 FpP\-+Sl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; qv.[k<~a>
for(int i=0;i<nStartPos.length;i++) IJ hxE
{ MNkKy(Za
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cge-'/8w%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $`^H:Djr
nStartPos,nEndPos,i); Zn?8\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }phz7N9
fileSplitterFetch.start(); 'g. :MQ8
} 8r2XGR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,yTN$K%M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {;U}:Dx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w+Ad$4Pf"
nEndPos = " + nFileLength); G"}qV%"6"
// fileSplitterFetch[nPos.length-1].start(); -s{R/6:
[Dnusp7e
RI?NB6U
//等待子线程结束 aLV~|$:2
//int count = 0; cB{%u '
//是否结束while循环 %rFP#L
boolean breakWhile = false; }%_qx|(P|t
.8-PB*vb
)8:n}w
while(!bStop) K3Huu!Tr
{ [0K=I64 z
write_nPos(); 1Pu ,:Jt
Utility.sleep(500); Q?Wr7
breakWhile = true; OdO{xG G@
{PL,VY)Z
baqn7k"
for(int i=0;i<nStartPos.length;i++) 7^HpVcSM
{ "_t4F4z
if(!fileSplitterFetch.bDownOver) X88F>1}
{ /#29Y^Z)=
breakWhile = false; wtlB
break; H1Q''$}Z.
} Mk<m6E$L
} EH(tUwY%{
if(breakWhile) FSv1X
break; %cS#+aK6M'
aWdUuid
6tX.(/+L
//count++; RTA%hCr!
//if(count>4) tAaYL \~
// siteStop(); S 9WawI
} Lg8]dBXu
D4d]3|/T
d"Bo8`_
System.err.println("文件下载结束！"); .Xi2G@D
} DQcWq'yY^
catch(Exception e){e.printStackTrace ();} 0(\p<qq
} .hxin[Y
D^$]>-^
S=4R5igrC
//获得文件长度 V_jiOT!
public long getFileSize() ,dOMW+{
{ vXc!Zg~
int nFileLength = -1; T{ok +$w2
try{ av$
URL url = new URL(siteInfoBean.getSSiteURL()); t`uc3ta"9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ) 9xX
httpConnection.setRequestProperty("User-Agent","NetFox"); V):`&@
f;R>Pr;rD
fD0{5
int responseCode=httpConnection.getResponseCode(); av)?>J~;
if(responseCode>=400) Sq<3Rw
{ #iiwD|
processErrorCode(responseCode); $khrWiX
return -2; //-2 represent access is error O!/ekU|,r
} ,b$z!dvhl
Ac J>$L)
L+7*NaPY*
String sHeader; 7$K}qsr<
$-Cy
#o~[1K+Yq
for(int i=1;;i++) j+nv=p
{ r-*l1([eW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %Sc=_%6
//Utility.log(in.readLine()); 1PmX."a
sHeader=httpConnection.getHeaderFieldKey(i); N_0pO<<cs
if(sHeader!=null) ::ri3Tu
{ HXyFj
if(sHeader.equals("Content-Length")) Q@3B{
{ gbJG`zC>U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !h?=Wv ==]
break; ,?I(/jI
} uO"y`$C$_
} /Ad6+cY
else _nP)uU$
break; w\p9J0
} Y^yG/F
} FQ1arUOFW,
catch(IOException e){e.printStackTrace ();} ghX:"vV{n
catch(Exception e){e.printStackTrace ();} $:(z}sYQ7
o7J{+V
E_]k>bf\
Utility.log(nFileLength); |g+!
} +1'{B"I
!KAsvF,j
return nFileLength; 9]Lo
} .izf#r:<
6vF/e#},
pcNSL'u+
//保存下载信息（文件指针位置） kwOeHdV^
private void write_nPos() y>)MAzz~\
{ eJW[ ]!
try{ }{A?PHV5
output = new DataOutputStream(new FileOutputStream(tmpFile)); j"i#R1T
output.writeInt(nStartPos.length); ?@>;/@
for(int i=0;i<nStartPos.length;i++) *CzCUu:%t
{ zx7#)*
// output.writeLong(nPos); xvdY 8%S
output.writeLong(fileSplitterFetch.nStartPos); 8sH50jeP
output.writeLong(fileSplitterFetch.nEndPos); BO]=vH
} *O5:
output.close(); l!/!?^8|f
} (m/aV
catch(IOException e){e.printStackTrace ();} =D}4X1l
catch(Exception e){e.printStackTrace ();} ~x\Cmu9`
} M.S s:ttj
svqvG7
-IbbPuRq
//读取保存的下载信息（文件指针位置） k},>^qE
private void read_nPos() y)tYSTJK
{ I.-v?1>,
try{ 9N^+IZ@l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :SK<2<8h
int nCount = input.readInt(); x_k S g
nStartPos = new long[nCount]; <$Ztik1
nEndPos = new long[nCount]; &lq^dFP&Su
for(int i=0;i<nStartPos.length;i++) gd_^
{ p0Z:Wkz]
nStartPos = input.readLong(); 8!;$qVt
nEndPos = input.readLong(); 7pP+5&*
} \1]rlzXGUT
input.close(); `On3/gU|
} P,U$ %C!
catch(IOException e){e.printStackTrace ();} d-h"JZ9
catch(Exception e){e.printStackTrace ();} t{6ap+%L
} CIEJql?`
X5 j=C]
ifvU"l
private void processErrorCode(int nErrorCode) P2t_T'R}
{ E0<)oQ0Xa>
System.err.println("Error Code : " + nErrorCode); 1#q^uqO0
} 5N1}Ns
EavX8r
S*xhX1yUi
//停止文件下载 @UV{:]f~e
public void siteStop() BKX9SL]
{ bQ"N ;d)e
bStop = true; 6< >SHw
for(int i=0;i<nStartPos.length;i++) Co[n--@C
fileSplitterFetch.splitterStop(); Tt%}4{"
[g`,AmR\!
7=vYO|a/4
} W_%W%i|
} S+iP^*L,c
//负责部分文件的抓取 $o"g73`3
**FileSplitterFetch.java SOs,)
*/ rd">JEK;;
package NetFox; /K@$#x_{
.yX>.>"T|
eG4>d^`c
import java.io.*; rFfy#e
import java.net.*; D'nL
&wb9_?ir-
!)nD xM`p
public class FileSplitterFetch extends Thread { [Y$V\h=V
d/lffNS=
aHC%19UN
String sURL; //File URL 9T?64t<Ju
long nStartPos; //File Snippet Start Position f1J%]g!
long nEndPos; //File Snippet End Position r6MB"4xd
int nThreadID; //Thread's ID <6R"h-u"
boolean bDownOver = false; //Downing is over R1/q3x
boolean bStop = false; //Stop identical JjQVzkE
FileAccessI fileAccessI = null; //File Access interface xDUaHE1co
P5Dk63z]
LXNQb6!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }PZ=`w*O
{ 7`dY1.rq
this.sURL = sURL; _ eiF@G
this.nStartPos = nStart; x9~[HuJ
this.nEndPos = nEnd; 4w;~4#ZPp
nThreadID = id; rREzM)GA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7*;^UqGjz
} C\A49q
,T{oy:rB
-X8eabb
public void run() EHhd;,;O
{ wV:C<Mg7q
while(nStartPos < nEndPos && !bStop) jtCZfFD?
{ )88nMH-
vhpvO>Q
)!sa)\E?
try{ e#khl9j*bt
URL url = new URL(sURL); Wcn[gn<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y"*:&E2)r
httpConnection.setRequestProperty("User-Agent","NetFox"); puF%=i
String sProperty = "bytes="+nStartPos+"-"; Z2bUs!0
httpConnection.setRequestProperty("RANGE",sProperty); R8 jovr
Utility.log(sProperty); v?)SA];
#w*"qn#2Uz
:,^>d3k
InputStream input = httpConnection.getInputStream(); GS4_jvD-
//logResponseHead(httpConnection); C_Gzv'C"L
.8(%4ejJ(
;UpJ=?W
byte[] b = new byte[1024]; Uouq>N
int nRead; wS%zWdsz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8gI\zgS
{ 5(#-)rlGj
nStartPos += fileAccessI.write(b,0,nRead); VMF|iB
//if(nThreadID == 1) W>/UBN3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o\goE^,aeR
} t!t=|JNf{
6v>z h
CKd3w8;
Utility.log("Thread " + nThreadID + " is over!"); (tKMBxQo8
bDownOver = true; + Kk@Q
//nPos = fileAccessI.write (b,0,nRead); u|OtKq
} :1MMa6
catch(Exception e){e.printStackTrace ();} .`J:xL%Z
} ,ux+Qz5(
} ]7vf#1i<
O,irpQ
?(D}5`Nfu
//打印回应的头信息 tN2 W8d
public void logResponseHead(HttpURLConnection con) LwQH6 !;[
{ yC"Zoa6YZ
for(int i=1;;i++) SQE` U
{ ?bI?GvSh
String header=con.getHeaderFieldKey(i); J3IRP/*z
if(header!=null) !Rqx2Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gQ+9xTd
Utility.log(header+" : "+con.getHeaderField(header)); h'!V8'}O?
else t7^D-l
break; KTv4< c]
} s#P:6]Ar
} u E.^w;~2=
_Wma\(3$
+>#e=nH
public void splitterStop() M5O'=\+,F
{ $eX*
bStop = true; s5AgsMq
} iC*U$+JG
O^NP0E
Mpm#GdT
} ^*>n4U
-)RJ\V^{9
]]/lC
/* }e2F{pQ
**FileAccess.java WsB3SFNG
*//文件访问(定位，写) ^1VbH3M
package NetFox; e1uMR-Q
import java.io.*; 2LK]Q/WG,+
]3+``vL
QiU_hz6?v
public class FileAccessI implements Serializable{ r0Z+RB^I
H+`*Y<F@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *B{-uc3o
RandomAccessFile oSavedFile; v$3_o :
long nPos; #_fY4vEO
?gG,t4D
>a@>N
public FileAccessI() throws IOException +?V0:Kz]
{ [+gzdLad
this("",0); pl\b-
} 4>k I^
-[$&s FD
JY@X2'>v/
public FileAccessI(String sName,long nPos) throws IOException >?V<$>12
{ )&z4_l8`=
oSavedFile = new RandomAccessFile(sName,"rw"); Pi){h~B>
this.nPos = nPos; L#ZLawG
oSavedFile.seek(nPos); (3O1?n[n
} KIIym9%
5~[N/Gl
~6sE an3p
public synchronized int write(byte[] b,int nStart,int nLen) H%C\Uz"o
{ yQwVQUW8B
int n = -1; waQtr,m)
try{ PkJcd->
oSavedFile.write(b,nStart,nLen); x.\XUJ4x
n = nLen; lY,/W
} T.2ZBG~|[
catch(IOException e) SSQT;>
{ i@6wO?Tv
e.printStackTrace (); $3 vhddO
} >%h7dC3h
R,b59,&3/
v F[CWV.
return n; o8tS
} 0[9I0YBJ
Mr.JLW
-#%X3F7/w
} PGY9*0n
A$<>JVv
pyF5S,c
/* XN(tcdCG
**SiteInfoBean.java {_7Hz,2U
*/ \k4pK &b
package NetFox; 8Z!*[c>K-?
+f|6AeE
IfB/O.;Kz
public class SiteInfoBean { *]2R.u
C fSl 54
n}:t<
private String sSiteURL; //Site's URL AsAFUuI
private String sFilePath; //Saved File's Path ls]H6z*q
private String sFileName; //Saved File's Name C$K+=jT
private int nSplitter; //Count of Splited Downloading File G *@@K
Y-]YDXrPQ
2Y;!$0_rv
public SiteInfoBean() HL8(lPgS
{//nSplitter的缺省值为5 5H*>
//default value of nSplitter is 5 M5 `m.n<
this("","","",5); ^]7,1dH}M
} x;mJvfX
]?&H^"=
QPV@'.2m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "Y(^F bs
{ ALAL( f`
sSiteURL= sURL; 6g|#ho1Bbs
sFilePath = sPath; @p6@a6N%
sFileName = sName; %yvA
this.nSplitter = nSpiltter; /Zx8nx'{V
6qDfcs
|lE-&a$xd
} o$\tHzB9!A
pI5_Hg
hb<k]-'!
public String getSSiteURL() :])JaS^
{ >[8#hSk
return sSiteURL; S\b K+
} niQcvnT4b
#]X2^ND47
sbA2W~:
public void setSSiteURL(String value) %ZuLl(
{ (Xj.iP
sSiteURL = value; >|(%2Zl
} z{' 6f@]
f)U6p
5}7ISNP;f
public String getSFilePath() p;e$kg1
{ T g{UK
return sFilePath; cyHU\!Z*Zq
} c>rKgx
{=6)SBjf
x,f>X;04
public void setSFilePath(String value) 5Edo%Hd6
{ -)6;0
sFilePath = value; "8?TSm8
} hMWo\qM
?DRR+n _
X?R |x[
public String getSFileName() :t%)5:@A
{ .v\PilF
return sFileName; S?2YJl8B
} H@4/#V|Uy
[n!x&f8Xh
m\?\6Wk
public void setSFileName(String value) E9L!)D]Y
{ DU`v J2
sFileName = value; 'QnW9EHLF
} |e+aZ%g
BtID;^Dz
M2L0c?
public int getNSplitter() +nzTxpcP@K
{ Y.X4*B
return nSplitter; DiR'p`b~
} <uC<GDO
E$R_rX4x
pkW5D
public void setNSplitter(int nCount) VW~Xbyf
{ VRB~7\A5<)
nSplitter = nCount; {Y^c*Iqn
} ozuIwzi7N
} s|E%~j[9
j<@fT ewZ
W.p66IQwL&
/* U&s(1~e\
**Utility.java {IrJLlq
*/ 7~D`b1||
package NetFox; (Wn "3 ]
l<Lz{)OR
?l>e75V%w
public class Utility { Y!aLf[x]
wM0E%6 P
&#Wkww&Y
public Utility() Bqp&2zg)@
{ Q~b_dx{m
boIVU`F-!
d _uFY:
} C6CGj8G
w~n kNqm
//线程睡眠 BPqwDjW
public static void sleep(int nSecond) YY\Rua/nG
{ h)P]gT0f/
try{ v/x*]c!"`
Thread.sleep(nSecond); @EYK(QS-
} (]}XLMi,|!
catch(Exception e) $M-NR||k
{ Z<I[vp6{
e.printStackTrace (); pb6 Q?QG,
} M",];h(I6(
} 1-/4Y5?}
Y6+k9$h
//日志 N:d D*[QZ
public static void log(String sMsg) PJ}[D.elO
{ \k4M{h6
System.err.println(sMsg); tfsh!)u?
} s 8Jj6V
ea>[BB3#
wD}EW
public static void log(int sMsg) _m" ^lo
{ <jg8y'm@0
System.err.println(sMsg); z}D#WWSxf
} @|Z*f\
} yTP[,bM
-GK'V
5vYsA1Z
/* 3/:LYvM<
**TestMethod.java 6OMb`A@/2
*/ ]yw_n^@
package NetFox; `9:v*KuM#R
/O+e#z2f<
[q w
public class TestMethod { b5[f 5
jzT;,4poy
K7+^Yv\YQx
public TestMethod() 9*f2b.Aj
{ ///xx/weblogic60b2_win.exe t ]71
try{ [9w, WJL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jt/l,=9YK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); py}.00it
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0@:Y>qVa
fileFetch.start(); .HQVj'g
} 38<~R
catch(Exception e){e.printStackTrace ();} t]gq+ c Lo
G[y&`Qc)G
]<Z&=0i#9
} S[ws0Y60
*1R##9\jU7
~>.awu+o|
public static void main(String[] args) {V{0^T-
{ ,o4r,.3[s
new TestMethod(); S$Qr@5
} 4RlnnXY
} _,11EeW@
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