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)); p$9N}}/c
} ~o # NOfYi
for(int i=0;i<nEndPos.length-1;i++) .{x5(bi0S
{ ;( 2uQ#Y
nEndPos = nStartPos[i+1]; q"52-42
} b/5~VY*T
nEndPos[nEndPos.length-1] = nFileLength; tQl=
} nQ~q-=,L
} uwQ4RYz
.FMF0r>l
D1g1"^~g
//启动子线程 uo%O\}#u9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \pPq]k
for(int i=0;i<nStartPos.length;i++) t]&n_]`{.
{ ^9{ 2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "t\9@nzdX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), IS=)J( 0
nStartPos,nEndPos,i); *M`[YG19!e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q?0goL
fileSplitterFetch.start(); 5cE[s<=
} Xif`gb6`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "R30oA#m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #F{|G:\@[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u8,T>VNVw
nEndPos = " + nFileLength); f Fz8m
// fileSplitterFetch[nPos.length-1].start(); jcG4h/A
XqwdJND
Sv>aZ
//等待子线程结束 x)Th2es\
//int count = 0; %vThbP#mR|
//是否结束while循环 _9gn;F
boolean breakWhile = false; ftH 0aI
CNN?8/u!@
d*AV(g#B
while(!bStop) 1)Ag|4
{ q;AQ6k(
write_nPos(); ;;`KkNysm
Utility.sleep(500); <_Lo3WGwc
breakWhile = true; q{5Vq_s\
OB^
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for(int i=0;i<nStartPos.length;i++) 4Sl^cKb$7
{ eo,]b1C2n
if(!fileSplitterFetch.bDownOver) 6/n;u{|
{ mcR!P~"i
breakWhile = false; Ebk@x=E
break; pucHB<R@bL
} V('b|gsEo
} 0ib 6}L%
if(breakWhile) p,0 \NUC
break; 7yj2we
v m$v[
zld>o3K}
//count++; 2>r.[
//if(count>4) @6Mo_4)O
// siteStop(); U!`'Qw;
} *K7L5.
x$p\ocA
}hf*Jw
System.err.println("文件下载结束！"); =0-qBodbl
} H9Z3.F(2
catch(Exception e){e.printStackTrace ();} KWYG\#S0]
} ^49moC-
g[n8N{s
Lr~K3nb
//获得文件长度 ?t"PawBWE
public long getFileSize() ditzl(L
{ x?F{=\z/o
int nFileLength = -1; 0CR;t`M@
try{ ;|%r!!#-t
URL url = new URL(siteInfoBean.getSSiteURL()); d"cfSH;h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (M=Br
httpConnection.setRequestProperty("User-Agent","NetFox"); uXC?fMWp.
O*PHo_&G
) jvkwC
int responseCode=httpConnection.getResponseCode(); zhe5i;M
if(responseCode>=400) -I*A `M
{ t5qAH++axN
processErrorCode(responseCode); s [!SG`&
return -2; //-2 represent access is error j AE0$u~.
} W7 E-j+2
z~_\onC
|)_R bqZ
String sHeader; %xruPWT:k
r/v&tU
+OmSR*fA0
for(int i=1;;i++) SrtmpQ
{ izw}25SW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h.^DRR^S
//Utility.log(in.readLine()); R;yAqr29
sHeader=httpConnection.getHeaderFieldKey(i); E6gEP0b
if(sHeader!=null) 2uTa}{/%
{ ww2Qa-K
if(sHeader.equals("Content-Length")) Ss:,#|
{ +g[B &A!d+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K_aN7?#.v`
break; a8 1%M
} rifxr4c[X>
} 9|`@czw
else #jJcgR<
break; MocH>^,
} &1{k^>oz
} m [g}vwS
catch(IOException e){e.printStackTrace ();} dNobvK
catch(Exception e){e.printStackTrace ();} Y<+4>Eh
|gz,Ip{
SDwSlwf
Utility.log(nFileLength); H^g<`XEgw
C] w< &o
6~S0t1/t?
return nFileLength; U!5*V9T~J
} (n/1:'
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<&2,G5XA
//保存下载信息（文件指针位置） =1VH5pVr}
private void write_nPos() gT OMD
{ lo:~~l
try{ ^IH1@
output = new DataOutputStream(new FileOutputStream(tmpFile)); qrc/Q;$
output.writeInt(nStartPos.length); [//f BO
for(int i=0;i<nStartPos.length;i++) \sd"iMEi
{ OpLSjr
// output.writeLong(nPos); N 3c*S"1
output.writeLong(fileSplitterFetch.nStartPos); }hYE6~pr
output.writeLong(fileSplitterFetch.nEndPos); G,-OH-M!
} j%;)CV G"
output.close(); F21[r!3
} ZL</
catch(IOException e){e.printStackTrace ();} ([*t.
catch(Exception e){e.printStackTrace ();} DcA'{21
} !&lPdEc@T
njMy&$6a##
~P_kr'o
//读取保存的下载信息（文件指针位置） ]Qr8wa>Z
private void read_nPos() ;l()3;
{ LDeVNVM
try{ GJs[m~`8#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); c!Vc_@V,
int nCount = input.readInt(); J36@Pf]h
nStartPos = new long[nCount]; L@r.R_*H?s
nEndPos = new long[nCount]; sV[Z|$&Z
for(int i=0;i<nStartPos.length;i++) Xb*_LZAU
{ h\d($Ki
nStartPos = input.readLong(); PEEY;x
nEndPos = input.readLong(); QtQ^"d65
} xUi!|c
input.close(); ;;!{m(;LS}
} o(/ia3
catch(IOException e){e.printStackTrace ();} o$VH,2 QF
catch(Exception e){e.printStackTrace ();} >;v0zE
} ;|QR-m2/
acY[?L_6J
p0y?GNQ
private void processErrorCode(int nErrorCode) f+Medc~
{ W;dzLgc
System.err.println("Error Code : " + nErrorCode); 2gAdZE&Y
} ,jsx]U/^
Z(mn U;9{v
O^weUpe\
//停止文件下载 YO$b#
public void siteStop() @^cgq3H'
{ [;?{BB
bStop = true; )]> '7] i
for(int i=0;i<nStartPos.length;i++) kZ-~ ;fBe
fileSplitterFetch.splitterStop(); 8'"/gC{
%@93^q[\2
n "KJB
} _np>({
} Uv`v|S:+2
//负责部分文件的抓取 jjT2k
**FileSplitterFetch.java MZW Y
*/ 0C+yq'D~[
package NetFox; X]MM7hMuR
[e@OHQM
P8,jA<W
import java.io.*; , )pt_"-XA
import java.net.*; H0n@kKr
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s*/ G- lY
public class FileSplitterFetch extends Thread { 36WzFq#
'3UIriY6
sk6|_
String sURL; //File URL ,tF" 4|#
long nStartPos; //File Snippet Start Position ^%$W S,
long nEndPos; //File Snippet End Position soQzIx
int nThreadID; //Thread's ID n;^k
boolean bDownOver = false; //Downing is over 7WfirRM
boolean bStop = false; //Stop identical 9Q7cUoxY
FileAccessI fileAccessI = null; //File Access interface OGi4m |
| ,l=v`/
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n[:AV
{ Q0uO49sg
this.sURL = sURL; YZ:'8<
this.nStartPos = nStart; m\Fb ,
this.nEndPos = nEnd; 5`'au61/2
nThreadID = id; T{{AZV"pB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MY*>)us\
} +6)kX4
2j/1@Z1j=
\3(|c#c
public void run() UH,4b`b
{ +fCyR
while(nStartPos < nEndPos && !bStop) k&_u\D"^"%
{ !QW 0
>`?+FDOJ,
VmH_0IM^6
try{ V<NsmC=g
URL url = new URL(sURL); b:5%}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [xs)u3b
httpConnection.setRequestProperty("User-Agent","NetFox"); QRZTT qG
String sProperty = "bytes="+nStartPos+"-"; 9Glfi@.
httpConnection.setRequestProperty("RANGE",sProperty); Ysc|kxLb
Utility.log(sProperty); VDu .L8
aU]O$Pg{
p9 ,\{Is
InputStream input = httpConnection.getInputStream(); q,,>:]f#
//logResponseHead(httpConnection); $s(4?^GP
qTa]th;
lp0T\ %
byte[] b = new byte[1024]; ]7R&m)16
int nRead; nK%/tdq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n.Eoi4jV'
{ vb.Y8[
nStartPos += fileAccessI.write(b,0,nRead); a(43]d&
//if(nThreadID == 1) i_'R"ob{S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "tz0ko,(
} p5# P r
]^6y NtLK
~)m t&
Utility.log("Thread " + nThreadID + " is over!"); qqt.nrQ^
bDownOver = true; NZ+?Ydr8k
//nPos = fileAccessI.write (b,0,nRead); 'oHOFH9:{b
} voej ~z+
catch(Exception e){e.printStackTrace ();} CWe>jlUQ
} Zc\h15+P
} A]O5+"mc
#9hXZr/8
QOh w
//打印回应的头信息 mLk6!&zN
public void logResponseHead(HttpURLConnection con) XAULD]Q
{ lF}$`6
for(int i=1;;i++) i h$@:^\
{ Aiks>Cyi23
String header=con.getHeaderFieldKey(i); ~ut& U
if(header!=null) ug6f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xlPcg7
Utility.log(header+" : "+con.getHeaderField(header)); K.iH
else Yr"!&\[oz
break; q{De&Bu
} &b@!DAwAJ
} 9p\wTzA
1nlE3Y?AV
{7![3`%7
public void splitterStop() {?>bblw/d
{ AR+\uD=\I-
bStop = true; s?G'l=CcKu
} jQ_|z@OV
5nxS+`Pn.)
N9JgV,`
} M8",t{7
8NAWA3^B
XC/]u%n8](
/* ?;r8SowZ7
**FileAccess.java X.T\=dm%v
*//文件访问(定位，写) =6Kv`
package NetFox; %M;_(jda
import java.io.*; rMXOwkE
/!{A=N
]g8i>,G
public class FileAccessI implements Serializable{ 4Fr7jD,#k
$`XN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FG;<`4mY
RandomAccessFile oSavedFile; B=Zukg1G
long nPos; hV>4D&<
@cS1w'=
sx-Hw4.a"
public FileAccessI() throws IOException I"F .%re
{ ><#2O
this("",0); mS)|6=Y
} vzohq1r5
&` 00/p
g@k#J"Q'[
public FileAccessI(String sName,long nPos) throws IOException y[^k*,= 9
{ ]4 K1%ZV
oSavedFile = new RandomAccessFile(sName,"rw"); .n)!ZN
this.nPos = nPos; az\<sWb#
oSavedFile.seek(nPos); S-M)MCL
} !}L~@[v,uL
i>]<*w
Av;q:x?
public synchronized int write(byte[] b,int nStart,int nLen) P+;CE|J`X
{ B.Zm$JZ:
int n = -1; veX"CY`hn
try{ z*dQIC
oSavedFile.write(b,nStart,nLen); e0~sUVYf
n = nLen; 1o;g1Z/
} n2jvXLJq
catch(IOException e) 2<6`TA*m
{ ax72ehL}
e.printStackTrace (); ~_l6dDJ
} ySixYt
y;{^Ln4{
c9*1$~(v0I
return n; x:A-p..e
} ?2?S[\@`0U
`\W
,N@Yk.
} H4}%;m%
HvqF@/xh
E VN-<=i^
/* j]!7BHC
**SiteInfoBean.java +&7[lsD*
*/ '#,e @v
package NetFox; B0b[p*gIl
(<bm4MPf
d%#!nq{vd
public class SiteInfoBean { m?D <{BQ;
tp6csS,
c%AFo]H
private String sSiteURL; //Site's URL .)"_Q/q
private String sFilePath; //Saved File's Path S1 EEASr!}
private String sFileName; //Saved File's Name [5?4c'Ev
private int nSplitter; //Count of Splited Downloading File 2qs>Bshf
VxkCK02k
z.2r@Psk
public SiteInfoBean() (|0.m8D~D
{//nSplitter的缺省值为5 BR& Aq
//default value of nSplitter is 5 hzT{3YtY2
this("","","",5); nabBU4;h
} 99l>CYXd
/~3N@J
y*VQ]aJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KA5~">l
{ AW,v
sSiteURL= sURL; V;h=8C5J
sFilePath = sPath; ,:#,}w_HyO
sFileName = sName; >63)z I
this.nSplitter = nSpiltter; <*s"e)XeqF
^[{`q9A#d
G"o!}
} S=0"f}Jo.
\H Wcd|
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public String getSSiteURL() :]P~.PD5,
{ _BZ1Vnv
return sSiteURL; CQ6'b,L&
} kzZDtI)
q"gqO%Wb|
qP~WEcH`[
public void setSSiteURL(String value) ,?l~rc
{ _j:UGMTi(U
sSiteURL = value; R)0N0gH
} \~JNQ&_o
+h0PR?
s kN9O"^A
public String getSFilePath() $> "J"IX
{ k:b/Gq`
return sFilePath; Q~Ay8L+
} v,/[&ASz
yXJ]U \ %
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public void setSFilePath(String value) X}ZlWJ
{ ;B&^yj&;
sFilePath = value; BjJ,"sT
} K)\(wxv
4p.^'2m
PG{i,xq_B{
public String getSFileName() ?b||Cr
{ >Bc>IO
return sFileName; D`6iDit
} s}6+8fE"
QX[Djz0H8
n[!;yO
public void setSFileName(String value) ;Vg^!]LL#
{ 1EVfowIl
sFileName = value; ^>C11v
} =96G8hlT
Zp?4uQ)[W
7ftR4
public int getNSplitter() ,4[dLWU
{ 4&Byl85q
return nSplitter; !c%
} lC0~c=?J
Q"40#RFA
O~V1Ywfq7^
public void setNSplitter(int nCount) A (Bk@;
{ {m[s<A(
nSplitter = nCount; n-DaX kK
} pet~[e%!
} JIzY,%`\
}91*4@B7
3y99O $EAc
/* KU-'+k2s;p
**Utility.java &VDl/qnaL
*/ 2d*_Qq1
package NetFox; \K;op2
4'',6KJ@
yL6^\x
public class Utility { nX|Q~x]
H@GE)I>^@
NUCiY\td
public Utility() U&X2cR &a
{ YutQ]zYA.
@5xu>gKn
(Yv{{mIy
} B MM--y@
T-'~?[v
//线程睡眠 ;f:gX`"\
public static void sleep(int nSecond) ^i+[m
{ l<(cd,
try{ En(7(qP6}
Thread.sleep(nSecond); H3, ut
} 8-m 3e
catch(Exception e) DECB*9O^
{ xACdZB(
e.printStackTrace (); 7Y1GUIRa3
} r`jWp\z
} %Tv^GP{}
gY(1,+0-
//日志 `0{ S3v
public static void log(String sMsg) 5,1{Tv`
{ U&UKUACn"
System.err.println(sMsg); Bq@zaMv
} iib
5u r)uz]w8
UZGDdP
public static void log(int sMsg) }g|nz8
{ 5{d\uE%'p
System.err.println(sMsg); %d1draL
} |t))u`~
} *RWm47
/)EY2Y'
EF#QH _X
/* 87V1#U^
**TestMethod.java lwT9~Hyp
*/ D'b#,a;V
package NetFox; %T!J$a)qf
?P/AC$:|I
6BocGo({
public class TestMethod { tu0aD%C
\}5p0.=
nPN?kO=]
public TestMethod() JN4fPGbV
{ ///xx/weblogic60b2_win.exe {^}0 G^
try{ ]E3<UR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ('C7=u&F
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fuUm}N7
SiteFileFetch fileFetch = new SiteFileFetch(bean); @*>Sw>oet
fileFetch.start(); C$d>_r
} }^-<k0A4?
catch(Exception e){e.printStackTrace ();} 4nqoZk^R
ibpzeuUl
@?kM'*mrZM
} $g10vF3
D\1k.tI
>\2:\wI
public static void main(String[] args) kL>d"w
{ hePPxKQ-
new TestMethod(); ?+0GfIV
} At6qtoPRA
} 1[;;sSp
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