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)); 9}kN9u
} BR\%aU$u
for(int i=0;i<nEndPos.length-1;i++) +NPk9jn
{ dC@aQi6{6
nEndPos = nStartPos[i+1]; 9Qp39(l:
} OxX{[|!`
nEndPos[nEndPos.length-1] = nFileLength; rKq/=Avv
} ?_[xpK()
} zLXmjrC
8WV1OIL
Rk^Fasg"
//启动子线程 =nOV!!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :7p0JGd
for(int i=0;i<nStartPos.length;i++) TCp!4-~,
{ 49}yw3-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2}]6~i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), AY:3o3M
nStartPos,nEndPos,i); 8 f%@:}H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ` 1DJwe2
fileSplitterFetch.start(); 2;%DE<Z
} )F&@ M;2p'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =If% m9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C1P{4 U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7P9n. [
nEndPos = " + nFileLength); 1Nw&Z0MI
// fileSplitterFetch[nPos.length-1].start(); ?UQVmE&
^4]#Ri=U
d9|dHJf
//等待子线程结束 #/@U|g
//int count = 0; ([UuO}m-
//是否结束while循环 AL! ^1hCF
boolean breakWhile = false; c&)H
Jl&bWp^3
BDxrSq,H
while(!bStop) Pca~V>Hd
{ sW+YfJT
write_nPos(); %Rr!I:[ $
Utility.sleep(500); KgVit+4u/
breakWhile = true; "e g`3v
%@$h?HP
q#v.-013r
for(int i=0;i<nStartPos.length;i++) QRdNi1&M
{ $ZYEH
if(!fileSplitterFetch.bDownOver) %0INtq
{ 0m)["g4
breakWhile = false; KM4w{
break; ~X5yHf3
} +,7dj:0S
} c a_N76o!
if(breakWhile) m{!BSl
break; )VJAs|
;|w &n
z=!$3E ecr
//count++; C!XI0d
//if(count>4) rfYu8-
// siteStop(); c }ivYH?`w
} MjE.pb
B P"PUl:
^j';4'
System.err.println("文件下载结束！"); l7aGo1TcIh
} Xn"n5=M
catch(Exception e){e.printStackTrace ();} m0]LY-t
} *x`z5_yfO
FFbMG:>:
<.$<d
//获得文件长度 dJ?VN!B0
public long getFileSize() Y+iC/pd
{ G#5Cyu<r!
int nFileLength = -1; @iUzRsl
try{ 3`TC*
URL url = new URL(siteInfoBean.getSSiteURL()); vQ+}rHf`[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3k;U#H
httpConnection.setRequestProperty("User-Agent","NetFox"); vi4 1`
/`\-.S9
vPmP<c)cb
int responseCode=httpConnection.getResponseCode(); h@Ea$1'e,
if(responseCode>=400) dVVeH\o
{ b-]E-$Uz
processErrorCode(responseCode); oHI~-{m3)
return -2; //-2 represent access is error XZcsx
} #i ?@S$
N$pwTyk
H24g+<Tv
String sHeader; POH>!lHu
qS&PMQ"$
'e3y|
for(int i=1;;i++) FvG9PPd
{ 8)5n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); l4U& CA y
//Utility.log(in.readLine()); $2]1 3j
sHeader=httpConnection.getHeaderFieldKey(i); MGc=TQ.
if(sHeader!=null) @EfCNOy
{ #H O\I7m
if(sHeader.equals("Content-Length")) z(.$>O&6H
{ L)8+/+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); a[";K,
break; @EO#Ms
} 1a_;[.s
} 7b+OIZB
else H!F'I)1
break; )FWF T:P~
} dadOjl)S)
} =e$ #m;
catch(IOException e){e.printStackTrace ();} zIF &ZYP
catch(Exception e){e.printStackTrace ();} [w=x0J&
bQXxb(^
6$ IXER
Utility.log(nFileLength); t vk^L3=<
JsnavI6
bIp;$ZHy`K
return nFileLength; `6~*kCj5
} #Yw^n?~~
G]P4[#5
:U)e 8
//保存下载信息（文件指针位置） bcM#KA
private void write_nPos() *Z{$0K
{ 1"/V?ArfL
try{ + A0@#:B
output = new DataOutputStream(new FileOutputStream(tmpFile)); qu[w_1%S
output.writeInt(nStartPos.length); 4c2P%X( C
for(int i=0;i<nStartPos.length;i++) &tWWb`
{ W3<O+S&
// output.writeLong(nPos); KNY<"b
output.writeLong(fileSplitterFetch.nStartPos); rFx2S
output.writeLong(fileSplitterFetch.nEndPos); V2g$"W?3
} LWVO%@)w
output.close(); wW%I <M
} !-N!80
catch(IOException e){e.printStackTrace ();} iS=T/<|?
catch(Exception e){e.printStackTrace ();} 30DpIkf
} P?9CBhN
EHzZ9zH\
"VT5WFj
//读取保存的下载信息（文件指针位置） P*aD2("Z
private void read_nPos() EAY9~b6~c
{ {q}:w{x9u
try{ >E]*5jqU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]m4LY.SQ
int nCount = input.readInt(); *r-Bt1
nStartPos = new long[nCount]; uXhp+q\
nEndPos = new long[nCount]; +B8Ut{l
for(int i=0;i<nStartPos.length;i++) e\yj>tQJg
{ UD9h5PgT
nStartPos = input.readLong(); s|,]Nb=z/
nEndPos = input.readLong(); ZM|>Va/X
} b%oma{I=.c
input.close(); G x,D'H'
} 1c}'o*K_%
catch(IOException e){e.printStackTrace ();} +Og O<P
catch(Exception e){e.printStackTrace ();} 20fCWVw}?}
} {;p/V\
8ZIv:nO$
(XW#,=rYk
private void processErrorCode(int nErrorCode) spl*[ d
{ qb"!
System.err.println("Error Code : " + nErrorCode); `Mjm/9+18
} Rp@u.C<
htF&VeIte
y:,{U*49
//停止文件下载 R(zsn;
public void siteStop() &1Y+q]
{ \]9;c6(
bStop = true; 3/[=
for(int i=0;i<nStartPos.length;i++) KDXo9FzF
fileSplitterFetch.splitterStop(); iEU(1?m2-
Etl7V
'@fk(~|
} 26Yg?:kP
} >)N#n`
//负责部分文件的抓取 Xs!eV
**FileSplitterFetch.java TM"-X\e~{
*/ ^-ACtA)
package NetFox; iF%q6R
SHGO;
.Z^g 7 *s
import java.io.*; B}MJ?uvA
import java.net.*; %]R#}amW
`Ch6"=t
P\M+ZA ;
public class FileSplitterFetch extends Thread { 8odVdivh
HhpP}9P;
$(NfHIX
String sURL; //File URL ~Fx[YPO,
long nStartPos; //File Snippet Start Position q6ikJ8E8b
long nEndPos; //File Snippet End Position kl={L{r
int nThreadID; //Thread's ID - a=yid
boolean bDownOver = false; //Downing is over %bimcRX#W
boolean bStop = false; //Stop identical q@\_q!
FileAccessI fileAccessI = null; //File Access interface sbs"26IE
xv*mK1e
Y{O&-5H^|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ex|kD*=
{ b9YpUm7#
this.sURL = sURL; +p[~hM6?
this.nStartPos = nStart; gO/(/e>P
this.nEndPos = nEnd; JxvwquI
nThreadID = id; =3T?U_u@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1y@-
} H,I}R
z=fag'fzM
kDz.{Ih
public void run() h49Q2`
{ {jVFlKP>
while(nStartPos < nEndPos && !bStop) C=]3NB>Jc
{ M ?3N
w %zw+E
6,7omYof
try{ U=t'>;(g
URL url = new URL(sURL); VsmL#@E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +sI.GWQ_:
httpConnection.setRequestProperty("User-Agent","NetFox"); a(7ryl~c=
String sProperty = "bytes="+nStartPos+"-"; xC{NIOYn'
httpConnection.setRequestProperty("RANGE",sProperty); x3P@AC$\
Utility.log(sProperty); esHiWHAC
xL BG}C
q)~qd$yMS
InputStream input = httpConnection.getInputStream(); 6+FON$8
//logResponseHead(httpConnection); b1#=q0Zl
t#q>U%!
Ocb2XEF
byte[] b = new byte[1024]; "h2Ny#
int nRead; |]q=D1/A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) saT9%?4-
{ %C)JmaQ{9
nStartPos += fileAccessI.write(b,0,nRead); p3S c4
//if(nThreadID == 1) [s/@z*,M1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cDx^}N!
} Wk|z\OR(
w=`z!x![/
O)Qz$
Utility.log("Thread " + nThreadID + " is over!"); @( t:E`8
bDownOver = true; z(WpOD
//nPos = fileAccessI.write (b,0,nRead); e?YbG.(E9
} y#0w\/<
catch(Exception e){e.printStackTrace ();} uaKB
} LnDj
} QdTe!f|
AH`15k_i
</X"*G't
//打印回应的头信息 .#@Dn(
public void logResponseHead(HttpURLConnection con) m\f_u*
{ (*ng$zZ$
for(int i=1;;i++) V\"5<>+O
{ [!le 9aNg
String header=con.getHeaderFieldKey(i); jE#8&P~
if(header!=null) CwvNxH#LVu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /RM-+D:Y
Utility.log(header+" : "+con.getHeaderField(header)); W,~1KUTc
else s2v*
break; b8>9mKs
} ddP,_.0
} h7$!wf!I
`$H
M@kZ(Rkv
public void splitterStop() qJA.+q.e$e
{ CiuN26>
bStop = true; }#8uXA
} ? st#6=M
0I((UA/7Zs
kKM%
} b..$5
Z-|C{1}A
\DqxS=o;
/* vI'>$
**FileAccess.java ~-`02
*//文件访问(定位，写) Bs?F*,zDJ
package NetFox; |esjhf}H>v
import java.io.*; fO^6q1a
u`@f~QP0
zfb _ )
public class FileAccessI implements Serializable{ c0&'rxi(B
v|@n8ED|@K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C8:"+;
RandomAccessFile oSavedFile; }qhK.e
long nPos; 5$U>M
kW&Z%k
qD*\}b]9I
public FileAccessI() throws IOException sK0VT"7K
{ F5+_p@!i
this("",0); gi'agB^
} A#S:_d
<UJJ],)^1A
7[BL 1HI*
public FileAccessI(String sName,long nPos) throws IOException |nN/x<v
{ 3|Sy'J0'K
oSavedFile = new RandomAccessFile(sName,"rw"); Uob|Q=MQ
this.nPos = nPos; NCnId}BT
oSavedFile.seek(nPos); %uVJLz
} _a$DY,;
U!:!]DX(
;J-Ogt@d7
public synchronized int write(byte[] b,int nStart,int nLen) ]t)M}^w
{ rJZs 5g`
int n = -1; ZT8Ji?_n
try{ Lzx$"R-
oSavedFile.write(b,nStart,nLen); 'S7@+kJ
n = nLen; \Z20fh2
} 3D{4vMmX
catch(IOException e) M#]|$\v(
{ n/oipiYx
e.printStackTrace (); d[e:}1
} |$w={N^4
jne9=Als5
6BU0hV
return n; mqk(UOK`
} ' P`p.5nH
yj'' \
`.(S#!gw
} \h7J/es^p!
Mp"ci+Iu
=+}}Sv2
/* BrH;(*H)8
**SiteInfoBean.java I.+)sB?5
*/ ClMtl59
package NetFox; *C@[5#CA2z
iW1ih QX
8;g.3Qv
public class SiteInfoBean { e=o{Zo?H=
mERrcYY{
h2"|tTm,a
private String sSiteURL; //Site's URL %C`'>,t>
private String sFilePath; //Saved File's Path GGc_9?h
private String sFileName; //Saved File's Name "Dl9<EZ
private int nSplitter; //Count of Splited Downloading File ?ey&Un"
MAe<.DHY
`x$}~rP&)!
public SiteInfoBean() BQ9`DYIb
{//nSplitter的缺省值为5 bI]UO)
//default value of nSplitter is 5 \As oeeF
this("","","",5); HS6Imi
} NnLhJPh
.aismc`=
y|;8:b32
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?FV7|)f
{ #EmffVtY
sSiteURL= sURL; R_>TEYZ
sFilePath = sPath; hG~]~ )
sFileName = sName; cxD}t'T
this.nSplitter = nSpiltter; Stw+Dm\!
ok3
a|P~LMPM
} B2G5hbaA
Z0"&
Naf`hE9
public String getSSiteURL() !*?(Q6
{ O:,2OMB}B`
return sSiteURL; a\&(Ua
} Ukx/jNyYv
c[h'`KXJf-
c. TB8Ol
public void setSSiteURL(String value) /;<e.
{ _7=pw5[
sSiteURL = value; iVKbGgA
} yF/< :
-.b Io
HTUYvU*-
public String getSFilePath() W7*_T]
{ ^3WIl]
return sFilePath; %on9C`/
} 9xK4!~5V
D]pK=247
Tw`c6^%^y
public void setSFilePath(String value) g<2lPH
{ I(^jOgYU
sFilePath = value; E+m]aYu"
} I|F~HUzA"
]{AOh2Z.hv
JA?,0S
public String getSFileName() e7XsyL'|p
{ _H4$$
return sFileName; 6+Wr6'kuH
} vZ[$H
l:zU_J6
(>rS _#^
public void setSFileName(String value) P~Te+ -jX}
{ 2fkIdy#n@
sFileName = value; h/ LR+XX!
} O1x0[sy
z-KrQx2
+ ZR(
public int getNSplitter() 3x"@**(Q
{ =2RhPD
return nSplitter; ,J~,ga~
} F!OOrW]p0
/S7+B]
]z-']R;
public void setNSplitter(int nCount) l zfD)TWb
{ ' "ZRD_"
nSplitter = nCount; )l+XDI
} #&^ZQs<
} H$~M`Y9I~
|8&-66pX
!X5o7b)
/* \LIy:$`8
**Utility.java ~In{lQ[QX
*/ S2J#b"Y
package NetFox; CrnB{Z4L
G$;>ueM
QD$}-D[
public class Utility { [c&2i`C
x @1px&^
tWpl`HH
public Utility() KI Ek/]<H
{ gCv"9j<j
Dk)@>l:gI,
gB(9vhj$
} Eyr5jXt%;
-Bo86t)F
//线程睡眠 *'Z-OY<V
public static void sleep(int nSecond) wrH7 pd
{ jZXVsd
try{ -M"IVyy@
Thread.sleep(nSecond); t{_!Z(Rt5)
} "DVt3E
catch(Exception e) 25xcD1*
{ wn &$C0
e.printStackTrace (); HA$Y1}
} r#LnDseW
} HzP.aw4
90Xt_$_}s
//日志 CdX`PQ
public static void log(String sMsg) B }6Kd
{ ~_ *H)|
System.err.println(sMsg); 9aTL22U?
} %lXbCE:[
7<^'DOs
n`P`yb\f$
public static void log(int sMsg) y7CWBTH0>
{ 5B}3GBA
System.err.println(sMsg); (FM4 ^#6
} @q,)fBZq
} Q2*/`L}m\
N1PECLS?
O x{Q.l
/* |kId8WtA
**TestMethod.java ;!'qtw"CB
*/ m'd^?Qc
package NetFox; ;xL67e%?
h]qT1(I
F vj{@B!
public class TestMethod { +Qt[1Xq
]x1p!TSU
^rL,&rk
public TestMethod() v#zPH5xo
{ ///xx/weblogic60b2_win.exe d{W}p~UbH
try{ TW>?h=.z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "hW(S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iDZrK%fl
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]x2Jpk99a
fileFetch.start(); e{5,'(1]
} xFOBF")
catch(Exception e){e.printStackTrace ();} :#WEx_]
.%_)*NUZ
4&|C}
} )B81i! q
d5Qd'
\[cH/{nt
public static void main(String[] args) 26M~<Ic
{ q&Q/?g>f
new TestMethod(); VO9XkA7
} [KMS<4t'
} V7P6zAJy
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