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)); D 1.59mHsD
} Nmx\qJUR(
for(int i=0;i<nEndPos.length-1;i++) ` 1+*-g^r
{ (m2%7f.I
nEndPos = nStartPos[i+1]; 1SjVj9{:
} q,ie)`
nEndPos[nEndPos.length-1] = nFileLength; 7=N%$]DKZ
} M%_*vD
} l\ dPfJ
}K'A/]'
SlB`ktcfI
//启动子线程 5b rM..
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Kc[^Pu
for(int i=0;i<nStartPos.length;i++) OF<:BaRs/
{ _:\rB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q(<A Yu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'G65zz
nStartPos,nEndPos,i); sBZn0h@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?M'CTz}<\
fileSplitterFetch.start(); |[n\'Xy;{
} --y,ky#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Pa{DB?P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g"sb0d9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4-[U[JJc
nEndPos = " + nFileLength); lB _9b_|2
// fileSplitterFetch[nPos.length-1].start(); ?H8w;Csq-
4e>f}u5
?&0CEfa?
//等待子线程结束 FMCA~N
//int count = 0; W2XWb<QSEV
//是否结束while循环 :a Cf@:']
boolean breakWhile = false; 9K}DmS
'E#L6,&
H 2I
while(!bStop) x(u.(:V
{ -}TP)/!,*
write_nPos(); [cDDZ+6
Utility.sleep(500); (zsmJe
breakWhile = true; aW:*!d#
@{qcu\sZ
H%n/;DW
for(int i=0;i<nStartPos.length;i++) j6^.Q/{^
{ ^kK")+K
if(!fileSplitterFetch.bDownOver) pWzYC@_W
{ a`yCPnB(
breakWhile = false; 4;~xRg;u&*
break; ww %c+O/
} br88b`L
} :@&e~QP(
if(breakWhile) 2A
break; ~L&z?'V
|goBIp[
Ow?~+) 4
//count++; a?Fz&BE
//if(count>4) @}UOm-M
// siteStop(); O(evlci
} N@0/=B[n
)X#$G?|Hn
uq6>K/~D
System.err.println("文件下载结束！"); '`}D+IQ(j
} sifjmNP
catch(Exception e){e.printStackTrace ();} M GC=L .
} 9Q(Lnu
zz3{+1w]
vB7]L9=@"
//获得文件长度 }c8et'HYf
public long getFileSize() %mlH
{ W{JR%Sq$
int nFileLength = -1; d>J +7ex+
try{ KDg%sgRu}
URL url = new URL(siteInfoBean.getSSiteURL()); /FXb,)1t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T^8`ji
httpConnection.setRequestProperty("User-Agent","NetFox"); 68~]_r.a
0@'-g^PS
D {E,XOi
int responseCode=httpConnection.getResponseCode(); 0RdW.rZJ
if(responseCode>=400) hT=E~|O
{ O:V.;q2]U
processErrorCode(responseCode); &Kc45
return -2; //-2 represent access is error %QDAog
} }}Q h_(
_JpTHpqu
wD
String sHeader; %j0c|u
agoMsxI9
F$v^S+Ch
for(int i=1;;i++) cPL6(&7
{ l}S96B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sFk{Tv@Yz
//Utility.log(in.readLine()); "OP$n-*@%
sHeader=httpConnection.getHeaderFieldKey(i); uG.`
if(sHeader!=null) @B+8' b$9
{ y\6C9%.
if(sHeader.equals("Content-Length")) G?s;L NR
{ 2CtCG8o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %> YRNW@%
break; h _c11#
} 0^P9)<k'
} =AK6^v&on
else gvjy'Rm
break; >0N$R|B&
} L!5="s[}
} F ww S[3
catch(IOException e){e.printStackTrace ();} sN[<{;K4
catch(Exception e){e.printStackTrace ();} hsws7sH
*bcemH8f
[A uA<
Utility.log(nFileLength); X|TGM
SX?hu|g_r
`sdbo](76
return nFileLength; U z)G Y
} 0rDQJCm
FGMYpapc~
#s=\
//保存下载信息（文件指针位置） wXeJjE%j:3
private void write_nPos() =6'D/| 3
{ Hg]iZ,8?
try{ %E":Wv
output = new DataOutputStream(new FileOutputStream(tmpFile)); ac43d`wpK
output.writeInt(nStartPos.length); yW(A0
for(int i=0;i<nStartPos.length;i++) >tkU+$;-
{ >Co@K^'
// output.writeLong(nPos); rt! lc-g%/
output.writeLong(fileSplitterFetch.nStartPos); zW95qxXg
output.writeLong(fileSplitterFetch.nEndPos); QUdF`_U7
} u"q!p5P%q
output.close(); Qz A)HDQ
} AdF[>Wv
catch(IOException e){e.printStackTrace ();} TY#pj
catch(Exception e){e.printStackTrace ();} XKBQH(
} fJ-8$w\uL
t2-bw6U
Ga"<qmLMc
//读取保存的下载信息（文件指针位置） Zg;Ht
private void read_nPos() bu\D*-
{ Wf *b"#
try{ wqn}t]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wGpw+O
int nCount = input.readInt(); 4y9n,~Qgw
nStartPos = new long[nCount]; l0wvWv*k
nEndPos = new long[nCount]; f;W>:`'
for(int i=0;i<nStartPos.length;i++) BjUz"69
{ y-7$HWn
nStartPos = input.readLong(); ps]s Tw
nEndPos = input.readLong(); J}&xS<
} 8+~|!)a
input.close(); ZnB|vfL?
} x6~`{N1N M
catch(IOException e){e.printStackTrace ();} / ='/R7~
catch(Exception e){e.printStackTrace ();} z:tu_5w!,
} [~rBnzb
j0K}nS\ P
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private void processErrorCode(int nErrorCode) jDM^e4U.l
{ kasx4m]^
System.err.println("Error Code : " + nErrorCode); z9*7fT
} GmLKg >%
WXE{uGc
DvXbbhp
//停止文件下载 (AgM7H0
public void siteStop() gcs8Gl2
{ D\GP+Ota
bStop = true; uw&'=G6v
for(int i=0;i<nStartPos.length;i++) @MGc_"b
fileSplitterFetch.splitterStop(); iu.+bX|b
I'RhA\`
@Nt$B'+S&
} #%tN2cFDN
} zFV?,"\r
//负责部分文件的抓取 "^@0zy@x
**FileSplitterFetch.java 4#@zn 2l
*/ s@bo df&
package NetFox; X5D}<J2"
H`ZUI8-
jJCd2O]
import java.io.*; Q2/ZO2
import java.net.*; E%C02sI
zpd Z.
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public class FileSplitterFetch extends Thread { }Pe0zx.Ge
{oN7I'>
i50^%,
String sURL; //File URL 8MPXrc,9-
long nStartPos; //File Snippet Start Position as6YjE.Yy
long nEndPos; //File Snippet End Position fg1["{\
int nThreadID; //Thread's ID snyg
boolean bDownOver = false; //Downing is over vSy#[9}
boolean bStop = false; //Stop identical B?J#NFUb
FileAccessI fileAccessI = null; //File Access interface U_c.Z{lC4
]`Y;4XR
:X;'37o#q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K%A:W
{ hK&/A+*
this.sURL = sURL; <$'OSN`!
this.nStartPos = nStart; GoNX\^A
this.nEndPos = nEnd; ,0=:06l
nThreadID = id; ajz%3/R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &iDX+*(
} 9n"D/NZB
thjCfP
bR!*z
public void run() BHw/~Hd4
{ @bj3N
while(nStartPos < nEndPos && !bStop) mmG+"g$|
{ (1(dL_?
HW(cA}$
Q<V?rPAcx
try{ *w538Vb
URL url = new URL(sURL); V'4sOn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q}M% \v
httpConnection.setRequestProperty("User-Agent","NetFox"); r0)X]l7
String sProperty = "bytes="+nStartPos+"-"; ga~C?H,K
httpConnection.setRequestProperty("RANGE",sProperty); "?GA}e"R
Utility.log(sProperty); Em8C +EM
ZVj/lOP X
0XBv8fg
InputStream input = httpConnection.getInputStream(); Rj9YAW$
//logResponseHead(httpConnection); A~6:eappH
%P2GQS-N
$5`P~Q'U
byte[] b = new byte[1024]; r-s.i+\
int nRead; ?E0j)P/ (
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gZe(aGh
{ 9a5x~Z:'
nStartPos += fileAccessI.write(b,0,nRead); #B3P3\
//if(nThreadID == 1) x_vaYUl)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z!P7mH\c}
} h7|#7 d
r9Wk7?w)
O$ 7R<V
Utility.log("Thread " + nThreadID + " is over!"); [;/ydE=
bDownOver = true; ShdE!q7
//nPos = fileAccessI.write (b,0,nRead); ;{79d8/=
} [wJM=`!W
catch(Exception e){e.printStackTrace ();} MV<2x7S
} 1>1&NQ#}
} Ap{p_~~iJ
a'zf8id
=Vv"\p8
//打印回应的头信息 >M\3tB2C
public void logResponseHead(HttpURLConnection con) E {$Jk]c
{ i"~J -{d}
for(int i=1;;i++) ]CD
{ xn'&TQo0
String header=con.getHeaderFieldKey(i); .|Pq!uLvc
if(header!=null) tO$/|B74Bz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \Q"j^4
Utility.log(header+" : "+con.getHeaderField(header)); IdsPB)k_
else 0HA`
break; eot]VO:
} g?.ls{H
} dC$z q~q
6px(]QU
-s5j^U{h|
public void splitterStop() [eebIJs
{ [%M=nJ{8
bStop = true; Wm{Lg0Nr
} ]3xb Q1
(*>%^C?
x$o?ckyH
} 2 5DXJb^:
iYi3x_A`
0drt,k
/* ,iKL 68
**FileAccess.java ]o18oY(
*//文件访问(定位，写) #"J8]3\F
package NetFox; 3":vjDq$
import java.io.*; U_t[J|
p.1@4kgK&r
Ib(q9!L
public class FileAccessI implements Serializable{ +>b~nK>M
DlHt#Ob7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .v?x>iV
RandomAccessFile oSavedFile; \wR $_X&
long nPos; !2-f%x]tO
_?"P<3/iF
lxIoP
public FileAccessI() throws IOException c]SXcA;Pmv
{ z>rl7&[@
this("",0); v]UT1d=_T
} |sP;`h}I%
\$.8iTr@
V2As 5
public FileAccessI(String sName,long nPos) throws IOException ZG29q>
{ wldv^n hM
oSavedFile = new RandomAccessFile(sName,"rw"); >yr:L{{D}G
this.nPos = nPos; } + ]A?'&
oSavedFile.seek(nPos); HjCWsQM
} N8hiv'3
N`3q54_$
dwd5P7
public synchronized int write(byte[] b,int nStart,int nLen) <$6r1y*G
{ {kCCpU
int n = -1; a_jw4"Sb
try{ |\/`YRg>
oSavedFile.write(b,nStart,nLen); gD}lDK6N
n = nLen; . V5Pr}"y
} <'n'>@
catch(IOException e) )ry7a .39b
{ US5]@!
e.printStackTrace (); "DN0|%`M/
} SlU?,)J}
d 8YP<"V&
MI^@p`s
return n; tB S+?N
} =E6ND8l@2
]Sj<1tx7f
M]c"4b;
} c`S`.WID
X:N`x
WP*xu-(:
/* /\L-y,>X
**SiteInfoBean.java 6pJFrWe{
*/ JXFPN|
package NetFox; >A5*=@7bY?
0R2KI,WI
WC&V9Yk
public class SiteInfoBean { <{ZDD]UGs0
$('"0 @fg
/b&ka&|t
private String sSiteURL; //Site's URL Dj?84y
private String sFilePath; //Saved File's Path l k~VvRq
private String sFileName; //Saved File's Name Pz\4#E]
private int nSplitter; //Count of Splited Downloading File (G1KMy
ZhqGUb
olm0O (9
public SiteInfoBean() !4.VK-a9V%
{//nSplitter的缺省值为5 JM&`&fsOC{
//default value of nSplitter is 5 o >wty3l:
this("","","",5); A9 *P7
} :.DZ~I
>m:;.vVY
Nxm^jPM0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $6[%NQp
{ Nm{+!}cC
sSiteURL= sURL; U/}("i![Dy
sFilePath = sPath; NL^;C3u
sFileName = sName; ~ 3!yd0[k
this.nSplitter = nSpiltter; u~O9"-m !V
Ew< sK9[o
ZVX1@p
} As{Q9o5j/
PF+F^;C
7MbV|gM}
public String getSSiteURL() Oj=g;iY
{ dI(1L~
return sSiteURL; "xI70c{
} }HCt=W`
'G1~ A +
] /"!J6(e
public void setSSiteURL(String value) 7|@FN7]5NF
{ C1`fJhy
sSiteURL = value; 2S
} V3S"LJ
WJlJD*3
m2a[E0
public String getSFilePath() ZGw6Bd_I
{ %!\iII
return sFilePath; +@^FUt=tq
} : uxJGx
sC'PtFK8z
).32Im!;#R
public void setSFilePath(String value) :Z[|B(U
{ h wi!C}
sFilePath = value; Gh5 3Pne
} 1Y:JGon
x'v-]C(@
r9Vt}]$aG
public String getSFileName() [-0=ZKH?
{ RRb>]oD
return sFileName; H73 r3BH
} Pk3b#$+E
swz)gh-*
5E#8F
public void setSFileName(String value) fKbg?
{ j6d{r\!$4
sFileName = value; *snY|hF
} %$<v:eMAs
XI'.L ~
tXCgRU
public int getNSplitter() HGao}@'
{ /[qLf:rGI
return nSplitter; #e[S+a
} ?!.L#]23f
% !>@m6JK
s7(1|}jh
public void setNSplitter(int nCount) v=_Ds<6n
{ en"\2+{Cg
nSplitter = nCount; }U^iVq*
} Xf;_r+;
} mwMcAUD]2
,`ba?O?*G
?>1wZ
/* i'B$Xr
**Utility.java Ou_2UT
*/ Obx!>mI^6
package NetFox; @rv)J[7Y&
q%/\
8]i7wq#=
public class Utility { v*kX?J#]5
g;7W%v5wqk
U UhlKV|5
public Utility() D/ tCB-+
{ G|I}x/X"Q7
BZa`:ah~x
pwvmb\
} ,z01*Yx
x21XzGLY|}
//线程睡眠 GMY[Gd
public static void sleep(int nSecond) <Zo{D |hW
{ n0FzDQt26
try{ ><C9PS@
Thread.sleep(nSecond); OWp`Wat
} RNopx3
catch(Exception e) ',1[rWyc
{ _4 YT2k
e.printStackTrace (); Qoa&]]
} dn&484
} Eb8~i_B-
1XpqnyL&
//日志 3U! l8N2
public static void log(String sMsg) y\n#`*5k
{ "[sr0'g:
System.err.println(sMsg); <OrQbrWQa
} h%5keiA
5S ) N&%
zCS&w ~
public static void log(int sMsg) F9>"1
{ 4,&f#=Y
System.err.println(sMsg); 1*f/Y9 Z
} y:Agmr,S
} Ih[k{p
ltv~Kh
ctPT=i60
/* &"=O!t2
**TestMethod.java / <+F/R'=O
*/ }&]T0U`@
package NetFox; tlYB'8bJY
N+vsQ!Qz
z2jS(N?J1
public class TestMethod { hb(H-`16
ex.^V sf_
lm*C:e)4A
public TestMethod() (/S6b
{ ///xx/weblogic60b2_win.exe 9RC:-d;;_
try{ FjW%M;H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @W=:r/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); I5]58Ohx
SiteFileFetch fileFetch = new SiteFileFetch(bean); s6DPb_,
fileFetch.start(); 9fYof
} +1K=]#a
catch(Exception e){e.printStackTrace ();} !FQS9SoO9
O' Mma5
@P">4xVX{
} M 9 N'Hk=
EL6<%~,V"I
<.ZD.u
public static void main(String[] args) Z^.qX\<M
{ (rQ)0g@
new TestMethod(); `j'gt&
} id)J;!^;J
} keJ-ohv)
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