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)); &b}!KD1
} lC6#EU;
for(int i=0;i<nEndPos.length-1;i++) "w`f>]YLA
{ _Bh-*l?K>
nEndPos = nStartPos[i+1]; Zg7~&vs$
} c3|;'s
nEndPos[nEndPos.length-1] = nFileLength; sp[nKo^
} J1"u,HF*(
} ..7"&-?g{4
gtz!T2%
+I2P{7
//启动子线程 C["^%0lj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g?(Z+w4A 3
for(int i=0;i<nStartPos.length;i++) 5SX0g(C
{ 9U58#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IqEY.2KN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L5cNCWpo
nStartPos,nEndPos,i); Tp<=dH%$%"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V/|Ln*rm
fileSplitterFetch.start(); 7 .+kcqX
} tF&%7(EU3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P _Zf(`jJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vsoj] R$C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h|%d=`P,
nEndPos = " + nFileLength); D}!U?]la&
// fileSplitterFetch[nPos.length-1].start(); sXl7
b_Ba0h=
hS +;HB,
//等待子线程结束 lyZof_/*
//int count = 0; "=|yM~V
//是否结束while循环 yN~=3b>
boolean breakWhile = false; SNff
cY#TH|M
Dw[w%uz
while(!bStop) ?Dm!;Z+7
{ Aid{PGDk
write_nPos(); r9s1\7]x
Utility.sleep(500); f|6%71
breakWhile = true; Z/;rM8[{&
o|alL-
;=)CjC8)
for(int i=0;i<nStartPos.length;i++) 9z_Gf]J~
{ e@0wF59
if(!fileSplitterFetch.bDownOver) |}q0G~l
{ Os@ofnC
breakWhile = false; S~/iHXm
break; W .Hv2r3
} PU?kQZU~)
} g"C$B Fc
if(breakWhile) 6tG9PG98q9
break; 51;(vf
-zc9=n<5
30<dEoF
//count++; %7 J
//if(count>4) @[ :sP
// siteStop(); [(btpWxb^
} =nid #<X
e>z7?"N
8%`Sx[
System.err.println("文件下载结束！"); 4f"be
} &,$A7:
catch(Exception e){e.printStackTrace ();} !0Q(x
} >r]# 77d
rKJ%/7m
-Qn:6M>w^
//获得文件长度 sUbZVPDr
public long getFileSize() $AsM 9D<BE
{ -'q=oTZ
int nFileLength = -1; 79x^zqLb
try{ 1Kc*MS
URL url = new URL(siteInfoBean.getSSiteURL()); "n]B~D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &Puu Xz<
httpConnection.setRequestProperty("User-Agent","NetFox"); lc5NC;JR
OvK_CN{
^Gd<miw
int responseCode=httpConnection.getResponseCode(); u5R^++
if(responseCode>=400) dr/!wr'&hS
{ 8sbS7*#
processErrorCode(responseCode); rSEJ2%iF*
return -2; //-2 represent access is error O]2h=M@q.
} ^`dp!1.+
},f7I^s|
)YnB6@=nyk
String sHeader; ~^5uOeTZ~
^R<= }
cL1cBWd
for(int i=1;;i++) n$=n:$`q
{ m CdkYN#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f%@Y XGf
//Utility.log(in.readLine()); CWDo_g$
sHeader=httpConnection.getHeaderFieldKey(i); dR=SW0Oa{
if(sHeader!=null) 41C=O@9m
{ ^OQ_iPPI
if(sHeader.equals("Content-Length")) nK96A.B%p
{ VUt 6[~?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]}5jX^j
break; 2qn~A0r
} -#Wc@\;
} xHL{3^
else BM3)`40[]
break; (wA|lK3
} 0`qq"j[6a
} $@#nn5^IX
catch(IOException e){e.printStackTrace ();} (ZI&'"H
catch(Exception e){e.printStackTrace ();} \+>b W(
Y5npz^i
68_UQ.
Utility.log(nFileLength); };KmMpBn
m3|,c[M1
[Q$"+@jw
return nFileLength; <Jvrmm[
} i2!{.*.
nC*/?y*9
Y}WO`+Vf5
//保存下载信息（文件指针位置） 43VuH
private void write_nPos() f~U|flL^
{ k1cBMDSokO
try{ 1R:h$*-z
output = new DataOutputStream(new FileOutputStream(tmpFile)); HmiwpI
output.writeInt(nStartPos.length); U{_O=S u
for(int i=0;i<nStartPos.length;i++) 5_i&}c23Vn
{ +,KuYa{lu
// output.writeLong(nPos); oC?b]tzj
output.writeLong(fileSplitterFetch.nStartPos); |zUDu\MZ{
output.writeLong(fileSplitterFetch.nEndPos); {&4qknPd%
} 0GG;o[<
output.close(); 6D+k[oHZm
} +tA rH C]
catch(IOException e){e.printStackTrace ();} jjbw.n+1
catch(Exception e){e.printStackTrace ();} );*GOLka
} f2Slsl;
(;M"'.C
8q0 .yhb
//读取保存的下载信息（文件指针位置） :kUH>O
private void read_nPos() MdKZH\z/
{ m|y]j4
try{ ~cez+VQe
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "8rP?B(
int nCount = input.readInt(); 9Z*vp^3
nStartPos = new long[nCount]; C8jZcs#4
nEndPos = new long[nCount]; q\/|nZO4
for(int i=0;i<nStartPos.length;i++) *V\kS
{ ]x Kmz
nStartPos = input.readLong(); \\T I4A^#
nEndPos = input.readLong(); )I<.DN&
} xv ja
input.close(); mPu5%%
} r*$"]{m}
catch(IOException e){e.printStackTrace ();} ?+!KucTF
catch(Exception e){e.printStackTrace ();} y^XwJX-f
} RHBEC@d[}
ewLr+8
<FJ#Hy+
private void processErrorCode(int nErrorCode) Gmwn:
{ J2R<'(
System.err.println("Error Code : " + nErrorCode); _Nj;Ni2rD
} JDs<1@\
[Cs2H8=#
Vr^wesT\Hx
//停止文件下载 Jk~T.p?tF
public void siteStop() V- vVb
{ $`Ou*
bStop = true; n-\B z.
for(int i=0;i<nStartPos.length;i++) +j<Nu)0iY
fileSplitterFetch.splitterStop(); 0s8S`hCn>
,aN/``j=
x?%vqg^r
} /yOd]N;$
} AiyjrEa%
//负责部分文件的抓取 qV}zV\Nz
**FileSplitterFetch.java s4Wk2*7Mq
*/ OUs2)H61
package NetFox; o+nU{
R_*\?^k|A
tQ)8HVKF
import java.io.*; $a-~ozr`C
import java.net.*; 55;xAsG
$+mmqc8
Gzs x0%`)
public class FileSplitterFetch extends Thread { n*;I2FV]
Y,8M[UIK
IOJfv8
String sURL; //File URL & =frt3
long nStartPos; //File Snippet Start Position FVSz[n
long nEndPos; //File Snippet End Position N( /PJJ~
int nThreadID; //Thread's ID uM\~*@
boolean bDownOver = false; //Downing is over c)lK{DC
boolean bStop = false; //Stop identical A$oYw(m#
FileAccessI fileAccessI = null; //File Access interface ~@-Az([H
e8[*=&
8IX6MfR}C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;Y~;G7
{ nc31X
this.sURL = sURL; |S4yol
this.nStartPos = nStart; S`R ( _eD@
this.nEndPos = nEnd; 5!5P\o
nThreadID = id; n3)g{K^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W=|B3}C?
} >g F
4];NX
TX*P*-'
public void run() PGybX:L
{ R sujKh/
while(nStartPos < nEndPos && !bStop) O@ "6)/
{ 2V
=}V`O>
Z|~<B4#c
try{ W9u(
URL url = new URL(sURL); ad"&c*m[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zcA"\
httpConnection.setRequestProperty("User-Agent","NetFox"); v&?Bqj
String sProperty = "bytes="+nStartPos+"-"; ^&,{
httpConnection.setRequestProperty("RANGE",sProperty); Z|j8:Ohz
Utility.log(sProperty); =GLsoc-b
:Z/ig%
>#V8l@IH
InputStream input = httpConnection.getInputStream(); .t["kaA
//logResponseHead(httpConnection); lID5mg31
'[A>eC++
5[@4($q8
byte[] b = new byte[1024]; q_W NN/w
int nRead; }we"IqLb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i=SX_#b^
{ m=n V$H
nStartPos += fileAccessI.write(b,0,nRead); H%/$Rqg
//if(nThreadID == 1) {~=[d`t
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `HHbQXB
} eR3!P8t
zL>nDnL 4
U2K>\/-~
Utility.log("Thread " + nThreadID + " is over!"); _o`'b80;
bDownOver = true; Maq{H`
//nPos = fileAccessI.write (b,0,nRead); 1W-!f%
} bb#w]!q
catch(Exception e){e.printStackTrace ();} s~TYzfA
} "PuP J|
} O,DA{> *m
QXF>xZ~
LtNG<n)_BH
//打印回应的头信息 %u!#f<"[
public void logResponseHead(HttpURLConnection con) m2 OP=z@)
{ JM M\
for(int i=1;;i++) AA@J~qd u
{ K;YK[M1!
String header=con.getHeaderFieldKey(i); dLo%+V#/A
if(header!=null) O[-wm;_(=*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8^HMK$
Utility.log(header+" : "+con.getHeaderField(header)); 1 iE
else y_a~>S
break; (I\aGGW
} (3_2h4O
} {)`5*sd
V&qXsyg
EI+.Q
public void splitterStop() f)*}L?
{ gmrjCLj
bStop = true; dp+wwNe
} bk"` hq
ww[STg
dmf~w_(7
} uD<*g(R
TCB<fS~U-
ZfMJU
/* :vc[ iZ
**FileAccess.java B<_T"n'#b
*//文件访问(定位，写) jp2l}C
package NetFox; >j\zj] -"
import java.io.*; Vrz<DB^-e
qxE~Moht
3A'd7FJ0G
public class FileAccessI implements Serializable{ '9i:b]Hru
UD"e:O_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L(}T-.,Slr
RandomAccessFile oSavedFile; E7y<iaA{~
long nPos; ~!Onz wmO
'0w'||#1
oXfLNe6>L
public FileAccessI() throws IOException y8 `H*s@
{ nuXaZRH
this("",0); 00<iv"8
} #&&^5r-b-
[L9e.n1
K2)),_,@5+
public FileAccessI(String sName,long nPos) throws IOException Q +qN`
{ RYmk6w!w
oSavedFile = new RandomAccessFile(sName,"rw"); +-HaYB|p
this.nPos = nPos; `/0X].s#o
oSavedFile.seek(nPos); Qp%kX@Z'
} IOt!A
<A+Yo3|7
`W{Ye=|[d#
public synchronized int write(byte[] b,int nStart,int nLen) qH"e: wgL
{ fv#e 8y
int n = -1; N'|zPFkg
try{ Kkdd}j
oSavedFile.write(b,nStart,nLen); =3""D{l
n = nLen; kXv -B-wOj
} 8vc4J5
catch(IOException e) ${mHbqN
{ }_XKO\
e.printStackTrace (); P4ot,Q4
} @ttcFX1:W
>:h 8T]F
X]Sr]M^EK
return n; 8`9!ocrM
} A+NLo[swwu
)7[>/2aGd
'2v,!G]^
} r'k-*I
3fn6W)v?
{v<Ig{{V
/* GfPe0&h
**SiteInfoBean.java 0t6s20*q
*/ (m~MyT#S
package NetFox; B1J+`R3OX
fHR1kuy
h}rrsVj3
public class SiteInfoBean { p*n$iroy_{
Wvmf[!V;
(\,mA-%E
private String sSiteURL; //Site's URL $Ob]JAf}
private String sFilePath; //Saved File's Path HFvhrG
private String sFileName; //Saved File's Name XR]]g+Z
private int nSplitter; //Count of Splited Downloading File ${0Xq k
%\%1EZQ%
Z9 }qds6 y
public SiteInfoBean() b]Oc6zR,,~
{//nSplitter的缺省值为5 i#iY;R8
//default value of nSplitter is 5 h$4V5V
this("","","",5); y @h^
} xL=g(FN(6L
NS mo(c>5
L&q~5 9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "f3, w
{ }0}J
sSiteURL= sURL; V]`V3cy1+3
sFilePath = sPath; Td X6<fVV
sFileName = sName; -P@o>#Em
this.nSplitter = nSpiltter; /$]dVvhX%
N y7VIh|
g}L2\i688
} X7Cou6r
ex&&7$CXc
SDcD(G
public String getSSiteURL() 6EP5n
{ ?)5}v4b
return sSiteURL; (~zdS.
} Eki7bT@/
Q^ bG1p//.
nRb#M
public void setSSiteURL(String value) ~|R"GloUw
{ @fPiGu`L
sSiteURL = value; V92e#AR
} \[+ZKj:
3Akb|r
I]jVnQ>&
public String getSFilePath() }m\
{ W(a=ev2sa
return sFilePath; FwmE1,
} )TVyRYZ1
P=(\3ok
#0hX)7(j
public void setSFilePath(String value) =DcKHL(m
{ Xp4pN{he
sFilePath = value; +w%MwPC7`
} OB;AgE@
Jg/WE1p>
/8Ca8Ju
public String getSFileName() Cp_"PvTmT
{ enDjP
return sFileName; y~]>J^
} pV:X_M6
NcB^qv
lHT?
public void setSFileName(String value) kYmkKl_
{ P0 hC4Sxf
sFileName = value; "qMd%RP
} pN1W|Wv2
7K%Ac
X3<<f`X
public int getNSplitter() Z r
{ ]M-j_("&
return nSplitter; "N D1$l
} q: ?6
G# .z((Rj
u\Tq5PYXt
public void setNSplitter(int nCount) "b|qyT* Sl
{ doW_vu
nSplitter = nCount; QUH USDT
} ROW8YTYb
} |9@?8\
&3:-(:<U
roVGS{4T\
/* p*8=($j4
**Utility.java rMdOE&5G
*/ wHEt;rc(
package NetFox; Kj;Q;Ii
*/u_RJ
zL+jlUkE
public class Utility { =j#uH`jgW
&)T5V
kL* DU`
public Utility() 6:fe.0H9
{ +>M^p2l*&
`gDpb.=Y
pW2NrBq@w
} |~Z.l
9i;%(b{
//线程睡眠 RpOGY{[)[
public static void sleep(int nSecond) y U =) g
{ K7 -AVMY
try{ zn@<>o8hU
Thread.sleep(nSecond); <v>^#/.0
} ^<}9#q/rt
catch(Exception e) %iPWg
{ ^Vso`(Ss
e.printStackTrace (); M ~zA
} J<'[P$D
} ,.A@U*j
3CL/9C>
//日志 2!Yq9,`
public static void log(String sMsg) Ye% e!
{ xQ+UZc
System.err.println(sMsg); Ti$G2dBO
} eyUguA<lK\
]V0V8fU|
}E0~'
public static void log(int sMsg) ~_8Dv<"a
{ `u$ Rd
System.err.println(sMsg); lR5[UKr
} /Jj7+?
} }Z#KPI8\Q
Ne#FBRu5
>Q3_-yY+
/* )O\w'|$G
**TestMethod.java 'K&^y%~py,
*/ C@d*t?
package NetFox; .8e]-^Z
'2Q[g0VR
|y1O M
public class TestMethod { A0X'|4I
2tD{c^ 9<
/5:2g#S4
public TestMethod() !z?&
{ ///xx/weblogic60b2_win.exe V6Z~#=EQ
try{ 3E9 )~$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2iM]t&^<+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -&q@|h'
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6`Hd)T5{w
fileFetch.start(); B|d-3\sn
} 3bYPi^
catch(Exception e){e.printStackTrace ();} BOt1J_;(rO
CWT#1L=
'3<T~t
} ^AhV1rBB
x{DTVa 6y2
3JYhF)G
public static void main(String[] args) |\.:h":!0~
{ |7%has3"
new TestMethod(); A1Ru&fd!
} AQ%B&Q(V1
} [~NJf3c"
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