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)); ,~38IIS>_
} +`gU{e,p
for(int i=0;i<nEndPos.length-1;i++) B*O/>=_
{ ~<<32t'S:
nEndPos = nStartPos[i+1]; ysG1{NOl
} CKZEX*mPC
nEndPos[nEndPos.length-1] = nFileLength; 0Yq_B+IC
} oY0b8=[
} _F[a2PE2+
\8<[P(!3
2HBey
//启动子线程 N".BC|r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; UW8yu.`?
for(int i=0;i<nStartPos.length;i++) u;H^4} OQ
{ P.q7rk<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dtY8>klI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `ql8y'
nStartPos,nEndPos,i); E_A5KLP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AEnkx!o
fileSplitterFetch.start(); dl8f]y#Q
} wT- -i@@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0_ST2I"Ln
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k6z ]-XG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qS! Lt3+
nEndPos = " + nFileLength); |-{e!&
// fileSplitterFetch[nPos.length-1].start(); bws}'#-*
t^KQv~
iR9duP+
//等待子线程结束 12'MzIsU's
//int count = 0; ,N,@9p
//是否结束while循环 24 [cU
boolean breakWhile = false; u? >x
cSB_b.@"1
8(Ptse ,
while(!bStop) n_]B5U
{ !:5'MI@
write_nPos(); w@R"g%k-
Utility.sleep(500); zfI{cMn'J
breakWhile = true; YI*H]V%w
G$'UK
9]ZfSn)
for(int i=0;i<nStartPos.length;i++) (-0d@eqw
{ :}fA98S
if(!fileSplitterFetch.bDownOver) (D?4*9=
{ }z/%b<o_
breakWhile = false; hNYO+LrI)
break; zQ,M795@EA
} I>l^lv&[+
} Lz_.m
if(breakWhile) q%q+2P>
break; g}Lm;gs!>
r ^*D8
2^`k6V!
//count++; _~yd
//if(count>4) EX!`Zejf
// siteStop(); xbw;s}B
} q>K3a1x
K@2"n| S;
Z-4/xi7
System.err.println("文件下载结束！"); Q6URaw#Yt`
} N.Q}.(N0
catch(Exception e){e.printStackTrace ();} seAPVzWUU
} #+_=(J
iuXXFuh
T zS?WYF
//获得文件长度 ,d lq2
public long getFileSize() i9qIaG/
{ sl@>GbnS
int nFileLength = -1; 4HZXv\$
try{ XABP}|aWK
URL url = new URL(siteInfoBean.getSSiteURL()); VuTTWBx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wBw(T1VN
httpConnection.setRequestProperty("User-Agent","NetFox"); Iy;"ht6
PU%f`)
jHE^d<=O^
int responseCode=httpConnection.getResponseCode(); z#`Qfvu6Hi
if(responseCode>=400) B>cT<B
{ l+&DBw[
processErrorCode(responseCode); Zw{?^6;cS
return -2; //-2 represent access is error icIWv
} C .B=E"e
x)eF{%QB
=a+ } 6
String sHeader; 2/A*\
H{i|?a)
=~W=}
for(int i=1;;i++) ci2Z_JA+
{ tcl9:2/^]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SvkCx>6/G
//Utility.log(in.readLine()); nIL67&
sHeader=httpConnection.getHeaderFieldKey(i); 3Ur_?PM+C
if(sHeader!=null) j@+$lU*r
{ "Vl4=W)u
if(sHeader.equals("Content-Length")) :Sd`4"AA
{ =E!Y f#p+q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cl4_M{~
break; (`#z@,1
} :t "_I
} 9(!AKKrr;
else hP.Km%C)0n
break; s3@mk\?qMe
} ]n"RPktx
} "LkBN0D
catch(IOException e){e.printStackTrace ();} b+arnKo1fk
catch(Exception e){e.printStackTrace ();} .I#_~C'\
iWA?FBv
B1U!*yzG6
Utility.log(nFileLength); GNrRc3dr$
l. cp[
cvT@`1
return nFileLength; rx9y^E5T`;
} ?>V>6cDQ
YjL'GmL<
c1a$J`
//保存下载信息（文件指针位置） a-FI`Dv
private void write_nPos() -nHkO&&R
{ [YODyf}M>\
try{ :O&jm.2m
output = new DataOutputStream(new FileOutputStream(tmpFile)); T2rBH]5
output.writeInt(nStartPos.length); iV#A-9
for(int i=0;i<nStartPos.length;i++) #+U1QOsz
{ 1$C?+H
// output.writeLong(nPos); [ "3s
output.writeLong(fileSplitterFetch.nStartPos); L{r4hL [
output.writeLong(fileSplitterFetch.nEndPos); ]i0=3H2
} 6=,zkU*i^
output.close(); zd!%7 UP
} xb0,dZb
catch(IOException e){e.printStackTrace ();} K*,,j\Q.
catch(Exception e){e.printStackTrace ();} ),Yk53G6c
} P?|\Ig1Gk
?mK&Slh.
3pW4Ul@e
//读取保存的下载信息（文件指针位置） Qmo}esb'(
private void read_nPos() {n|Uf 5
{ rMjb,2*rC7
try{ kF,ME5%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /)K;XtcN
int nCount = input.readInt(); I 2OQ
nStartPos = new long[nCount]; 5cU:wc
nEndPos = new long[nCount]; =6=:OId
for(int i=0;i<nStartPos.length;i++) 's5rl
{ 0QfDgDX
nStartPos = input.readLong(); -Hw3rv3o
nEndPos = input.readLong(); +%K~
} vV9vB3K5?
input.close(); _&s pMf
} 8qw{e`c
catch(IOException e){e.printStackTrace ();} =23@"ji@D
catch(Exception e){e.printStackTrace ();} olxxs(
} xHaz*w1|
/2/aMF(J
M&faa7
private void processErrorCode(int nErrorCode) QT%vrXzz
{ ao.vB']T
System.err.println("Error Code : " + nErrorCode); a.?U$F
} ~Sm6{L
>35w"a7S
_$D!"z7i
//停止文件下载 O_.!qk1R
public void siteStop() qAbmQ{|w
{ eu_ZsseZ
bStop = true; (/]#G8
for(int i=0;i<nStartPos.length;i++) 5}]+|d;
fileSplitterFetch.splitterStop(); [ @"6:tTU
.%.7~Nu,
hp9LV2_5
} `]6<j<' ,
} e`7>QS;.
//负责部分文件的抓取 VX8CEO
**FileSplitterFetch.java U{pg y#/
*/ xJ. kd Tr
package NetFox; z;<~j=lP
&Q}%b7
U{[YCs fk
import java.io.*; vZ srlHb
import java.net.*; {}Is&^3Z
aD'Ax\-
i(cKg&+ktd
public class FileSplitterFetch extends Thread { c@}t@k
Tt{z_gU6
</xf4.C
String sURL; //File URL R@tEC)Zn
long nStartPos; //File Snippet Start Position "gm5DE
long nEndPos; //File Snippet End Position m9:ah<
int nThreadID; //Thread's ID ;i?2^xe^~c
boolean bDownOver = false; //Downing is over /JC1o&z_T
boolean bStop = false; //Stop identical ?vAhDD5
FileAccessI fileAccessI = null; //File Access interface vF'>?O?
;sAGTq
oxL<\4)WJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dc1Zh W4
{ g<0K i^#
this.sURL = sURL; T=M##`jP%
this.nStartPos = nStart; CZeZk
this.nEndPos = nEnd; AgSAjBP
nThreadID = id; 62_k`)k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~;Y Tz
} X_@|+d
"qR, V9\
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public void run() 2=8PA/
{ H2#o X
while(nStartPos < nEndPos && !bStop) 9Scg:}Nj
{ dz+Dk6"R
,~ZD"'*n6g
,3f>-mP
try{ GCO: !,1
URL url = new URL(sURL); `<>QKpAn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kI@<H<
httpConnection.setRequestProperty("User-Agent","NetFox"); ?0*[ L
String sProperty = "bytes="+nStartPos+"-"; rEj[XK
httpConnection.setRequestProperty("RANGE",sProperty); c};%VB
Utility.log(sProperty); Z/?{{}H+
FE,mUpHIR
?jlz:Z4
InputStream input = httpConnection.getInputStream(); E JuTv%Y8
//logResponseHead(httpConnection); <y^_&9
@/^mFqr2
Mkk.8AjC|
byte[] b = new byte[1024]; _[Imwu}
int nRead; m=^]93+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $,, PF/N8c
{ F5/,S
nStartPos += fileAccessI.write(b,0,nRead); Bh cp=#
//if(nThreadID == 1) ZnI15bsDx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m<>BxX
} P,'%$DLDg
_\tv ${
I%a-5f$0
Utility.log("Thread " + nThreadID + " is over!"); AzXLlQ
bDownOver = true; ]2)A/fOW
//nPos = fileAccessI.write (b,0,nRead); j"h/v7~
} zEW+1-=)+7
catch(Exception e){e.printStackTrace ();} JOt(r}gU
} Y01!D"{\
} e]88 4FP
ug2W{D
ycc G>%>r
//打印回应的头信息 LAxN?ok9gD
public void logResponseHead(HttpURLConnection con) H2Wlgt
{ 8^j~uH
for(int i=1;;i++) j+ -r(lZ
{ 0: hv6Ge^
String header=con.getHeaderFieldKey(i); YuknZ&Q
if(header!=null) /R=MX>JA;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r W[;3yMf
Utility.log(header+" : "+con.getHeaderField(header)); `DgK$QM
else miQ*enZi
break; =NC??e{
} *4`5&) `
} ={oNY.(Q
J$1H3#VVG
\b(&-=(
public void splitterStop() ~KMah
{ N2A6C$s
bStop = true; '0q$qN
} ;;+AdN5
Nv36#^Z
iD_y@+iz
} KU` *LB:
T&]-p:mg^
|JYb4J4Ni
/* QWfSm^ t
**FileAccess.java {P~rf&Ee
*//文件访问(定位，写) d8jH?P-"
package NetFox; naf ~#==vc
import java.io.*; ySO\9#Ho
9c)#j&2?H
#vV]nI<MF.
public class FileAccessI implements Serializable{ _(h=@cv
A[;deHg=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 MYy58N
RandomAccessFile oSavedFile; 4mo/MK&M:
long nPos; 0N>K4ho6{
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oHx:["F
public FileAccessI() throws IOException bGeIb-|(
{ ; o_0~l=-/
this("",0); Hm'"I!jyO
} %w65)BFQ
0x-g0]
!mUJ["#
public FileAccessI(String sName,long nPos) throws IOException ^)>( <6
{ PtW2S 1?j
oSavedFile = new RandomAccessFile(sName,"rw"); m#RJRuZ|2V
this.nPos = nPos; gUx}vE-
oSavedFile.seek(nPos); g-d{"ZXd J
} 63u%=-T%a
VmPh''Z%-
#4$YQ
public synchronized int write(byte[] b,int nStart,int nLen) raPOF6-_rH
{ a&8K5Z%0
int n = -1; >tcEx(
try{ ;Y*K!iFWH
oSavedFile.write(b,nStart,nLen); iXnXZ|M
n = nLen; ftPps-
} (y>N\xS9
catch(IOException e) d[3me{Rs
{ G:$kGzhJ
e.printStackTrace (); 15j5F5P
} c 1F^Gj!8
C+s/KA%
X#$ oV#
return n; Nz`8)Le
} "crR{OjE"
T/P\j0hR
q\o#<'F1J
} AEyD?^?
x7zc3%T's
]z^jz#>um&
/* cl^UFlf[
**SiteInfoBean.java V[/9?5pM
*/ 06.%9R{
package NetFox; N+c|0
q%;cu1^"M
qK%N{ro[{?
public class SiteInfoBean { xQvI$vP
[l5jPL}6
[#gm[@d,
private String sSiteURL; //Site's URL 9/0H,qZc
private String sFilePath; //Saved File's Path *>=tmW;%
private String sFileName; //Saved File's Name }}TPu8Rl
private int nSplitter; //Count of Splited Downloading File /8qR7Z^HZ
9abUh3
a[~[lk=7
public SiteInfoBean() GCN-T1HvA2
{//nSplitter的缺省值为5 L.@$rFhA
//default value of nSplitter is 5 |9S8sfw
this("","","",5); <h/q^|tZ{
} $EFS_*<X
i;%G Z8
!I?C8)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2: gh q
{ -"nkC
sSiteURL= sURL; IwnDG;+Ap
sFilePath = sPath; c.]QIIdK
sFileName = sName; 0<`qz |_h
this.nSplitter = nSpiltter; }kmAUaa,Z
a8T9=KY^
cOP'ql{"
} e#HPU
5CK\Z'c~!
A_@..hX(
public String getSSiteURL() ?Sh]kJO
{ /W,hOv
return sSiteURL; 0j!<eN=
} _WWC8?6U
3:jxr
r[Pp[g-J
public void setSSiteURL(String value) 3\m!
{ Lld45Bayb
sSiteURL = value; ++,I`x+p
} A` _dj}UF
;?HP/dZLz
4Y59^
public String getSFilePath() N/0aO^"V
{ :} =lE"2
return sFilePath; [x{$f7CEh
} SV t~pE+Y
1<m`38'
L-?ty@-i
public void setSFilePath(String value) x*z&#[(0g!
{ Jt]RU+TB
sFilePath = value; QYo04`Rl
} :& Dv!z
kfas4mkc
N@PwC(
public String getSFileName() p}pRf@(`\
{ #>aq'47j
return sFileName; +g?uvXC&
} > .NLmzUX
"G>d8GbIh
n! 5(Z5=
public void setSFileName(String value) r*b+kSh
{ 9RlJf=Z#H
sFileName = value; afX|R
} O MQ?*^eA
~`BkCTT
Ich^*z(F$
public int getNSplitter() @*vVc`;
{ M2cGr
return nSplitter; i=<;$+tW
} cu>(;=
}6a}8EyFP
)@DDs(q=i
public void setNSplitter(int nCount) =!SV;^-q
{ 1]''@oh{6U
nSplitter = nCount; NL:-3W7vf
} {?lndBP<
} m BvO<?ec
/Yi4j,8!|
nyPeN?-
/* rVP\F{Q4Tr
**Utility.java 0e0)1;t\
*/ H'#06zP>5
package NetFox; AcuZ?LYzK
,(q] $eOZ
grE(8M
public class Utility { 0#TL$?=|
?u:`?(\
L~/,;PHN
public Utility() f$:Y'$Z1
{ lv/im/]v
l9uocP:D
3 orZBT
} I]d-WTd
!{+CzUo@
//线程睡眠 'MW%\W;
public static void sleep(int nSecond) M *w{PjU
{ ( gg )?
try{ AJB NM
Thread.sleep(nSecond); sm'_0EUg
} E`_T_O=P
catch(Exception e) B /uaRi%
{ %C`P7&8m=O
e.printStackTrace (); P`@Rt
} ]:LlOv$
} U%bm{oVn
z<9C-
//日志 *;}xg{@
public static void log(String sMsg) D*2*FDGI
{ s i2@k
System.err.println(sMsg); 3);P!W4>
} "|I.j)
$=diG
hO[_ _j8
public static void log(int sMsg) |oU I2<"
{ kiJ=C2'&
System.err.println(sMsg); Hre&a!U
} <o|fH~?X
} c6 &k?Puy
rzHBop-8
rK'Lvt@w
/* b||usv[or
**TestMethod.java J:W+'x`@
*/ #pPOQv:~
package NetFox; .*YF{!R`h
)B $Q
QWa@?BO2p
public class TestMethod { W8bp3JX"
DgcS@N
%J2Ad
public TestMethod() b?OA|JqX
{ ///xx/weblogic60b2_win.exe (${:5W
try{ ,Tar?&C:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \&+Y;:6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }*rSg .
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]wDqdD y7S
fileFetch.start(); qdZ ^D
} eY#^vB
catch(Exception e){e.printStackTrace ();} Vx.c`/
X<IW5*
oS$7k3s fj
} D$4GNeB+#
8/j|=Q,5
r ezp7
public static void main(String[] args) 4+>yL+sC%v
{ bP-(N14x+
new TestMethod(); b-8@_@f|g
} {+#{Cha
} i|z=WnF$&
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