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)); AMqu}G
} : sIZ+3
for(int i=0;i<nEndPos.length-1;i++) G#V5E)Dx
{ w`XwW#!}@$
nEndPos = nStartPos[i+1]; Yo0%5 noz
} 7Cf%v`B4D
nEndPos[nEndPos.length-1] = nFileLength; FI@2KM
} 6S?a57;&W
} ^Q8m)0DP
n=v4m_e
it!i'lG
//启动子线程 !fdni}f)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {#M=gDhbX
for(int i=0;i<nStartPos.length;i++) qmUq9bV
{ 9_IR%bm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }D.?O,ue
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?#]K54?
nStartPos,nEndPos,i); Yjz'lWg
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iqf+rBL
fileSplitterFetch.start(); -k\7k2
} )f#@`lf[<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y{y #us1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^EU&6M2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'R6D+Vk/
nEndPos = " + nFileLength); @'[w7HsJ
// fileSplitterFetch[nPos.length-1].start(); QI>yi&t
QC>I<j&`!
'qLk"
//等待子线程结束 j9C=m"O
//int count = 0; 5n;|K]UW
//是否结束while循环 p}uTqI
boolean breakWhile = false; M64zVxsd
.FK'TG
&B3Eq1A
while(!bStop) {y0*cC
{ :K{`0U&l5
write_nPos(); tF)K$!GR[
Utility.sleep(500); Lc^nNUzPo
breakWhile = true; $I_04k#t
IBl}.o&]B#
l/OG79qq
for(int i=0;i<nStartPos.length;i++) >j?5MIm03
{ E*Vx^k$
if(!fileSplitterFetch.bDownOver) YlOYgr^
{ 4@#1G*OO
breakWhile = false; k1>%wR
break; {npKdX
} aA%$<ItH
} >rlQY>5pH
if(breakWhile) "%ag^v9
break; L.(T"`-i
Y">tfLIL_
|w[}\#2
//count++; R@>R@V>c
//if(count>4) [a;lYsOsJ
// siteStop(); )Y~q6D K
} hXS'*vO"
bf3LNV|
"n '*_rh>+
System.err.println("文件下载结束！"); G/(oQA
} fT._Os?i
catch(Exception e){e.printStackTrace ();} mquna"}N
} &dvJg
9In&vF7$
H_;Dq*
//获得文件长度 ` 2|~Z H
public long getFileSize() hX)r%v:
{ =pWpHbB.
int nFileLength = -1; /0SG
try{ &{&lCBN
URL url = new URL(siteInfoBean.getSSiteURL()); H*|Bukgt/M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &.kg8|s{
httpConnection.setRequestProperty("User-Agent","NetFox"); t,N-|
.5L/<
s5|LD'o!
int responseCode=httpConnection.getResponseCode(); 7x9YA$IE
if(responseCode>=400) &m8B%9w
{ cv:nlq)
processErrorCode(responseCode); !=&]#-;b
return -2; //-2 represent access is error 9YHSL[
} SfJ/(q
k;zbq
g/+M&k$
String sHeader; l@1f L%f
sLbz@54
toTAWT D
for(int i=1;;i++) /dOQ4VA\
{ =i%2/kdi0b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PyYKeo=
//Utility.log(in.readLine()); 0x^$q? \A
sHeader=httpConnection.getHeaderFieldKey(i); pY=?r{@
if(sHeader!=null) spO?5#
{ o~P8=1t
if(sHeader.equals("Content-Length")) b{sE#m%r
{ 1:YDN.*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s>~&:GUwR
break; 9[T#uh!DC
} JPQ02&e
} Xki/5roCQ|
else 8SAz,m!W)
break; q*{"6"4(
} UMhM8m!=o
} &[*<>
catch(IOException e){e.printStackTrace ();} 08k1 w,6W
catch(Exception e){e.printStackTrace ();} *B:{g>0
7M;Y#=sR
QH\*l~;B\
Utility.log(nFileLength); ^fK8~g;rB
~w]1QHA'f
,eUMSg~P.7
return nFileLength; 5tq$SF42X
} MiRH i<g0
\TMRS(
<S$y=>.9
//保存下载信息（文件指针位置） w5n>hz_5
private void write_nPos() nj7Ri=lyS
{ w5|@vB/pj
try{ '2[ _U&e
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^"buF\3L
output.writeInt(nStartPos.length); Bl`e+&b
for(int i=0;i<nStartPos.length;i++) 6w1:3~a
{ Kyl(
// output.writeLong(nPos); dje3&a
output.writeLong(fileSplitterFetch.nStartPos); )0}obPp
output.writeLong(fileSplitterFetch.nEndPos); LiV]!*9$KG
} >^InNJd
output.close(); u]dpA
} y Fp1@*ef
catch(IOException e){e.printStackTrace ();} Ds}6{']K
catch(Exception e){e.printStackTrace ();} Wnf`Rf)1z
} |=%$7b\C
a}>GQu*y
J.?p?-"
//读取保存的下载信息（文件指针位置） |um)vlN;9
private void read_nPos() vN4X%^:(
{ 7gQt k
try{ r1?LKoJOn
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A{+ZXu}
int nCount = input.readInt(); -;~_]t^a
nStartPos = new long[nCount]; wkm SIN:
nEndPos = new long[nCount]; pu>LC6m3a
for(int i=0;i<nStartPos.length;i++) ~Q%QA._R?
{ R*&3i$S
nStartPos = input.readLong(); ;QEGr|(
nEndPos = input.readLong(); -5>g 0o2
} T@vVff
input.close(); uo%O\}#u9
} Q o=
catch(IOException e){e.printStackTrace ();} t]&n_]`{.
catch(Exception e){e.printStackTrace ();} ^9{ 2
} KPO((G0&
lJYv2EZ
\uPT-M*
private void processErrorCode(int nErrorCode) H+ M~|Ju7
{ Ppp&3h[dW)
System.err.println("Error Code : " + nErrorCode); &Y#9~$V=
} HE,wEKp
6)bfd^JYn
s[s^z<4G
//停止文件下载 9n%W-R.
public void siteStop() ljf9L:L
{ ]g)%yuox9F
bStop = true; ovfw_
for(int i=0;i<nStartPos.length;i++) 1Gqtd^*;
fileSplitterFetch.splitterStop(); dl;A'/(t
|ITg-t
UNAuF8>K
} ?t%5/
} <kM%z{p
//负责部分文件的抓取 q;AQ6k(
**FileSplitterFetch.java ?41| e+p
*/ >qgBu_
package NetFox; 2 rBF<z7
#F6ak,9S4
cM"I3
import java.io.*; oz0-'_
import java.net.*; :m~lgb<
~g,QwaA[
_j2`#|oG
public class FileSplitterFetch extends Thread { @v'<~9vG
%FRkvqV*
dW5z0VuB$/
String sURL; //File URL i)p__Is
long nStartPos; //File Snippet Start Position ;s!H
long nEndPos; //File Snippet End Position 07MLK8jS
int nThreadID; //Thread's ID #nxx\,i>
boolean bDownOver = false; //Downing is over u4nXK <KL|
boolean bStop = false; //Stop identical xAO]u[J
FileAccessI fileAccessI = null; //File Access interface h7w<.zwu t
U!`'Qw;
*K7L5.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (l^lS=x
{ \ lKQ'_
this.sURL = sURL; <;T7qEIlo
this.nStartPos = nStart; @kK=|(OB'
this.nEndPos = nEnd; s1FBz)yCY=
nThreadID = id; D|BN_ai9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 />oU}m"k
} N1$P6ZF
"LWp/
-Tt}M#W
public void run() $k?L?R1
{ >*(>%E~H
while(nStartPos < nEndPos && !bStop) M]{!Nx
{ sd6Wmmo
#}Cwn$
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try{ {!S/8o"]
URL url = new URL(sURL); .edZKmC6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G@'0vYb#
httpConnection.setRequestProperty("User-Agent","NetFox"); K_xOY *
String sProperty = "bytes="+nStartPos+"-"; h^c'L=dR
httpConnection.setRequestProperty("RANGE",sProperty); Qi}LV"&L
Utility.log(sProperty); ][mc^eI0s|
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f:SF&t*
InputStream input = httpConnection.getInputStream(); }:irjeI,
//logResponseHead(httpConnection); |)_R bqZ
%xruPWT:k
&Y>u2OZ
byte[] b = new byte[1024]; -$q/7,os
int nRead; |{nI.>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LKZI@i)
{ }X?*o`sW
nStartPos += fileAccessI.write(b,0,nRead); aVb]H0
//if(nThreadID == 1) *l^'v9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d7P @_jO6
} ba ?k:b
KWUz]>Z
0_EF7`T
Utility.log("Thread " + nThreadID + " is over!"); f#t^<`7
bDownOver = true; xRUYJ=|oh
//nPos = fileAccessI.write (b,0,nRead); @rMW_7[y
} 9|`@czw
catch(Exception e){e.printStackTrace ();} O+$70
} MocH>^,
} &1{k^>oz
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("6W.i>
//打印回应的头信息 H-W)Tq_?-
public void logResponseHead(HttpURLConnection con) m0"\3@kB
{ 6Ts`5$e
for(int i=1;;i++) "=(;l3-o
{ &^H "T6
String header=con.getHeaderFieldKey(i); h~@+M5r,
if(header!=null) [ lW "M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #77UKYj2L-
Utility.log(header+" : "+con.getHeaderField(header)); U VKN#"_{
else ^4[[+r
break; %np#Bv-L
} "Zk6B"o)
} .7FI%
yh:,[<q
Z]f2&
public void splitterStop() x,dv~QU
{ q@9i3*q;
bStop = true; mmL~`i/
} ;Y^RF?un
<^Tj}5)n
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} )mdNvb[*n
7 L\?
to 6Q90(
/* y7OG[L/
**FileAccess.java g-FZel
*//文件访问(定位，写) Ak Tw?v'
package NetFox; H\mVK!](D
import java.io.*; %#9~V
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DZRxp,
public class FileAccessI implements Serializable{ [{F7Pc
!@{[I:5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SZ{cno1`
RandomAccessFile oSavedFile; sV[Z|$&Z
long nPos; Xb*_LZAU
h\d($Ki
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public FileAccessI() throws IOException bOMP8{H,
{ sjgR \`AU
this("",0); 0 0&$SE
} R+0"B
Rk%M~D*-
+3>/,w(x
public FileAccessI(String sName,long nPos) throws IOException x 5Dt5Yp"o
{ {Ch"zuPX
oSavedFile = new RandomAccessFile(sName,"rw"); (H+[^(3d2
this.nPos = nPos; v:MS0]
oSavedFile.seek(nPos); 2TEeP7
} K)&XQ`&
8$UZL
vw] D{OBv*
public synchronized int write(byte[] b,int nStart,int nLen) tQ JH'YV
{ [V, ;X
int n = -1; t[,T}BCy.
try{ ddDJXk)!0
oSavedFile.write(b,nStart,nLen); Y&f[2+?2NK
n = nLen; 3b@1Zahz
} jA4v?(AO}#
catch(IOException e) $L8s/1up
{ ,7jiHF
e.printStackTrace (); *.%)rm
} x[W]?`W3r~
-#;VFSz,9*
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return n; jjT2k
} MZW Y
<S@mQJS!y
l=~99mE
} EJaaW&>[
L_ qv<iM$
RK:sQWG
/* /{MH'
**SiteInfoBean.java efkie}
*/ b%f2"e0g
package NetFox; 1=5'R/k
zRoEx1
x ETVtq
public class SiteInfoBean { R 4QwWSBJ
e=)*O
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private String sSiteURL; //Site's URL _AHB|P I
private String sFilePath; //Saved File's Path O\F^@;]F6
private String sFileName; //Saved File's Name 0*IY%=i
private int nSplitter; //Count of Splited Downloading File :'rZZeb'
bA^:p3
[-Tt11
public SiteInfoBean() %802H%+
{//nSplitter的缺省值为5 YZ:'8<
//default value of nSplitter is 5 m\Fb ,
this("","","",5); 5`'au61/2
} T{{AZV"pB
MY*>)us\
obc^<ZD]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~K#_'Ldrd
{ 4f[M$xU&h
sSiteURL= sURL; %3#I:>si
sFilePath = sPath; LOUKUReE
sFileName = sName; $17 v,
this.nSplitter = nSpiltter; 4U a~*58
B0XBI0w^Y
WlRZ|.
} &T/q0bwd
^_S-s\DW
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public String getSSiteURL() h-+a;![
{ -KJ!
return sSiteURL; OK2/k_jXN'
} '"fU2M<.
C`~4q<W'
:f !=_^}
public void setSSiteURL(String value) {9|$%4kRl
{ Iam-'S5
sSiteURL = value; ny_ kr`$42
} {p*hNi)0
yH"$t/cU"R
i&'^9"Z)O
public String getSFilePath() [FV=@NI
{ ':2*+
return sFilePath; )"c]FI[}
} L1!hF3G
a.`JS
~iR!3+yg4
public void setSFilePath(String value) si!9Gz;
{ >7(~'#x8A"
sFilePath = value; :*&9TNUE@
} 73s3-DS,
>[%.h(h/%
`\4JwiPo
public String getSFileName() Wh'_slDH+
{ ;GgQ@s@
return sFileName; 2*FWIHyf
} D.&eM4MZ
~SR(K{nf#.
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public void setSFileName(String value) E%2!C/+B
{ >]XaUQ-
sFileName = value; 71<PEawL
} cH*/zNp
N4` 9TN7
p`<e~[]a
public int getNSplitter() o )nT
{ wp]7Lx?F
return nSplitter; D_19sN@0m
} N}x/&e
kG;eOp16R
^2;(2s
public void setNSplitter(int nCount) pW3)Y5/D
{ @a.6?.<L
nSplitter = nCount; 3e!Yu.q:
} &DbGyV8d"|
} 0q>NE<L
$kD`$L@U
4z0R\tjT
/* w1"gl0ga$
**Utility.java Xx y Bg!R
*/ & L.PU@
package NetFox; _^xh1=Qr}n
X\3,NR,
|!xfIR>=F
public class Utility { il>x!)?o
nzE,F\k
v1"g!%U6
public Utility() ej"o?1l@
{ 8F`BJ6='
\{MrQ2jd
w[,?-Xm
} gSv[4,hXd
L%o65
//线程睡眠 Lr24bv\
public static void sleep(int nSecond) =N@)CB7a
{ L`HH);Ozw
try{ e1 {t0f
Thread.sleep(nSecond); we H@S
} A}#]g>L
catch(Exception e) -|k&L}\OB0
{ S4{Mu(^xT
e.printStackTrace (); %];h|[ax]
} 1 ~B<
} =UB*xm%!
FUzMc1zy|
//日志 6Bq~\b^
public static void log(String sMsg) l#5~t|\
{ B::4Qme
System.err.println(sMsg); LpiHoavv
} 7$1fy0f[l
#E$Z[G]
_']%qd"%
public static void log(int sMsg) ,>QMyI hv
{ *b6I%MZn
System.err.println(sMsg); dIk8TJ
} fOK+DT~
} 9Ew:.&d
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/+x#V!zM
/* wzDk{4U
**TestMethod.java c+Q.?vJ
*/ t4jd KYA
package NetFox; )O2Nlk~l&
>2|[EZ
]e@0T{!
public class TestMethod { Uxk[O
]M+VSU
Z92iil;t
public TestMethod() ~|r'2V*
{ ///xx/weblogic60b2_win.exe O ':0V
try{ $TD~k;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [w&#+h-q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O2`oe4."vd
SiteFileFetch fileFetch = new SiteFileFetch(bean); JGk3b=K
fileFetch.start(); s.R-<Y3
} 68koQgI[^
catch(Exception e){e.printStackTrace ();} ( K6~Tj
`x{.z=xC
Sc4obcw%
} sFQ4O- SM
M1/M}~
;0w^ud
public static void main(String[] args) rP^TN^bd|
{ 2qs>Bshf
new TestMethod(); H[BD)
} E-yT
} O6m.t%*
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