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)); }XUI1H]jk
} i^:#*Q-co
for(int i=0;i<nEndPos.length-1;i++) 1hi
{ aO}hE2]
nEndPos = nStartPos[i+1]; w6>P[oW
} %k?/pRv$>
nEndPos[nEndPos.length-1] = nFileLength; y,rdyt
} rd%uc~/
} p9G+la~;VM
|PYyhY
99:.j=
//启动子线程 ))dqC l
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E71H=C 4
for(int i=0;i<nStartPos.length;i++) ZaaBg
{ M9fQ,<c<6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !!ZGNZ_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Qh8pOUD0l}
nStartPos,nEndPos,i); C[Q4OAFG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Xsanc@w)^C
fileSplitterFetch.start(); /#{~aCOi)
} &m36h`tM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1Z_w2D*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ux^ue9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uIO?4\s&G
nEndPos = " + nFileLength); %/\sn<6C}
// fileSplitterFetch[nPos.length-1].start(); Vr& GsT
hJ%$Te
X xwcvE
//等待子线程结束 hEo$Jz`
//int count = 0; lUq`tK8
//是否结束while循环 $aT '~|?
boolean breakWhile = false; YwH Fn+
0wqw5KC
tr0kTW$Ad
while(!bStop) m7A3i<6p
{ \cX9!lHl
write_nPos(); Y@UW\d*'%I
Utility.sleep(500); =7kn1G.(
breakWhile = true; ?G9DSk?6%Z
PQF 40g1}
1bw$$QXC_
for(int i=0;i<nStartPos.length;i++) NODg_J~T
{ wS$ 'gKA6
if(!fileSplitterFetch.bDownOver) N1y,~Z
{ `;R$Ji=>
breakWhile = false; P^q!Pye
break; Fm&f
} iSX:H;
} r da: ~
if(breakWhile) ESIeZhXVH
break; =b)!l9TX
&432/=QSm0
tmoclK-
//count++; =NK'xPr
//if(count>4) %qrUP\rn
// siteStop(); P?8$VAkj
} ]-heG'y]{
BdvpG
g[ @Q iy
System.err.println("文件下载结束！"); d[;&2Jz*
} VJr~h "[
catch(Exception e){e.printStackTrace ();} HDE5Mg "
} Yu[MNX;G
3$_- 0>
'wBOnGi6
//获得文件长度 "Rf|o6!d
public long getFileSize() JNvgUb'U
{ 51AA,"2[_
int nFileLength = -1; Mg^A,8lrm
try{ $`C$|9S
URL url = new URL(siteInfoBean.getSSiteURL()); xo-}t5w6t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5Ktll~+:#
httpConnection.setRequestProperty("User-Agent","NetFox"); ZWB3R
axXR-5c
=(,kjw88w
int responseCode=httpConnection.getResponseCode(); op&j4R
if(responseCode>=400) QS,_=< (
{ s9u7zqCF
processErrorCode(responseCode); Z#;\Rb.x7
return -2; //-2 represent access is error C}o^p"M*B3
} 1iM(13jW
d(Yuz#Qcrh
?IO3w{fmH
String sHeader; 4!M0)Nix
eNFA.*p<
=k!F`H`/%'
for(int i=1;;i++) `;Fs
{ D/2;b;-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qV$0 ";d
//Utility.log(in.readLine()); Zc9S[ivq
sHeader=httpConnection.getHeaderFieldKey(i); c-?0~A
if(sHeader!=null) xaIe7.Z"xo
{ PB{5C*Y7^k
if(sHeader.equals("Content-Length")) T(kG"dz
{ /hGu42YG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0}Qd
break; HN&]`cr;
} 8vvNn>Q
} }OgZZ8-_M
else 3KKq1][
break; f(-3d*g
} Xu{S4#1
} r?Pk}Q
catch(IOException e){e.printStackTrace ();} OF(tCK
catch(Exception e){e.printStackTrace ();} yMb.~A^$J
lR]SGdY
5PKdMEK|q
Utility.log(nFileLength); <QK2Wc_}-"
;q2e[y
qd [Z\B
return nFileLength; B o[aiT
} 04#r'UIF
ZV:0:k.x
?uE@C3 e
//保存下载信息（文件指针位置） be&,V_F
private void write_nPos() Snas:#B!
{ 'n!Sco)C
try{ 7t/C:2^&
output = new DataOutputStream(new FileOutputStream(tmpFile)); Io)@u~yz
output.writeInt(nStartPos.length); ?OWJUmQ
for(int i=0;i<nStartPos.length;i++) t. kOR<
{ |uln<nM9
// output.writeLong(nPos); %R*-oQ1T
output.writeLong(fileSplitterFetch.nStartPos); v6KF0mqA&
output.writeLong(fileSplitterFetch.nEndPos); ljO t~@Ea
} -(![xZ1{K
output.close(); 4kf8Am(
} CC`Y r
catch(IOException e){e.printStackTrace ();} +C9l7 q
catch(Exception e){e.printStackTrace ();} RD'i(szi?
} %3$EV}dp
ns !Mqcm
kT4Tb%7KM
//读取保存的下载信息（文件指针位置） 1bJrEXHXy
private void read_nPos() A{QA0X!p
{ AU^5N3%j
try{ Fop'm))C8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p EbyQ[
int nCount = input.readInt(); ioS(;2F
nStartPos = new long[nCount]; y[sO0u\
nEndPos = new long[nCount]; 7 a_99?J
for(int i=0;i<nStartPos.length;i++) =G%L:m*
{ =LMM]'no,
nStartPos = input.readLong(); d,caOE8N
nEndPos = input.readLong(); )*n2,n
} @t?uhT*Z=
input.close(); O0,=@nw8.
} |4|j5<5
catch(IOException e){e.printStackTrace ();} `%S#XJU
catch(Exception e){e.printStackTrace ();} %w3"B,k'9D
} Omy<Y@$
)wueR5P
E(G&mfhb
private void processErrorCode(int nErrorCode) $fl+l5?9
{ a EmLf
System.err.println("Error Code : " + nErrorCode); ,fW%Qv
} C{8(ew
lr_c
P+t`Rw
//停止文件下载 Ov PTgiI!N
public void siteStop() "s5[w+,R
{ @fG'X
bStop = true; rWB/#m
for(int i=0;i<nStartPos.length;i++) Dk`(Wgk2
fileSplitterFetch.splitterStop(); r:Rk!z*
}:a:E~5y
8[xl3=
} EgT?Hvx:
} @Lf-=9
//负责部分文件的抓取 g<$q#l~4xH
**FileSplitterFetch.java TQg~I/
*/ %#$K P
package NetFox; U[t/40W}P
xb~8uD5
@j|=M7B
import java.io.*; c 1o8
import java.net.*; 6@; P
#:LI,t
d| OEZx
public class FileSplitterFetch extends Thread { $I }k>F
DZE@C^0%
_?QVc0S!
String sURL; //File URL #9ZHt5T=$
long nStartPos; //File Snippet Start Position x|lX1Mh$
long nEndPos; //File Snippet End Position }*9mNE
int nThreadID; //Thread's ID \olYv!f
boolean bDownOver = false; //Downing is over I$w:qS&:
boolean bStop = false; //Stop identical Iu|4QE
FileAccessI fileAccessI = null; //File Access interface pDV8B/{
A{Dy3tm=
/@QPJ~%8Ud
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @pkQ2OM 2
{ Usz O--.C
this.sURL = sURL; >#~>!cv6D
this.nStartPos = nStart; YwnYTt
this.nEndPos = nEnd; oZwu`~h Y
nThreadID = id; hWD%_"yhd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -b$m<\0*
} FH7h?!|t
ee\QK,QV
#$0*Gd-N
public void run() !}PZCbDhL
{ BMs?+
while(nStartPos < nEndPos && !bStop) w9]HJ3qi
{ 2U.'5uA"L
;G|#i?JJ
' >R?8Y
try{ x,:DL)$1
URL url = new URL(sURL); 5~GH*!h%;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,zVS}!jRhy
httpConnection.setRequestProperty("User-Agent","NetFox"); ]m<z
String sProperty = "bytes="+nStartPos+"-"; >&%#`PKT
httpConnection.setRequestProperty("RANGE",sProperty); q)PLc{NO
Utility.log(sProperty); Bx9v2x.
d.Ep#4
GLWEoV9<
InputStream input = httpConnection.getInputStream(); $@^*lUw
//logResponseHead(httpConnection); v1}9i3Or#
5DxNHEuS
13K|=6si
byte[] b = new byte[1024]; ^n~bx*f
int nRead; 1'4?}0Dok
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +LwwI*;b
{ _{&bmE
nStartPos += fileAccessI.write(b,0,nRead); =}UcYC6l
//if(nThreadID == 1) =k^ d5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hnBX enT6
} @|'$k{i
DA_}pS"
wU(!fw\
Utility.log("Thread " + nThreadID + " is over!"); *w$3/
bDownOver = true; ]@{l<ExP
//nPos = fileAccessI.write (b,0,nRead); 9oQ$w?=#$
} PT39VI =
catch(Exception e){e.printStackTrace ();} )0?u_Z]w9
} -]<<}@NF
} H[2W(q6
%Hu?syo
AjD?_DPc
//打印回应的头信息 ,s`4k?y
public void logResponseHead(HttpURLConnection con) 4@r76v}{
{ c"lblt5
for(int i=1;;i++) QERj`/g
{ w:aV2
String header=con.getHeaderFieldKey(i); A9Icn>3?`(
if(header!=null) F[KM0t!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `G:I|=#w
Utility.log(header+" : "+con.getHeaderField(header)); *aW:Z6N
else QWwdtk
break; )|wC 1J!L
} =A{s,UP
} Pl\NzB,`
Ruv`yfQ
)~-r&Q5d
public void splitterStop() j:E3c\a
{ ~E/=nv$
bStop = true; r'4Dj&9Ac
} N<b~,[yCd>
T;]Ob3(BpW
9Y@ eXP
} z;MPp#Y
o/ 7[ G
^$X|Lq
/* 34Cnbtq^
**FileAccess.java "dT"6,
*//文件访问(定位，写) 4Y1dkg1y
package NetFox; GS7'pTsYH
import java.io.*; M|Nh(kvH
i[ >U#5
U#&+n-npO
public class FileAccessI implements Serializable{ OL%}C*Zq
r*dNta<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P)#h4|xZ
RandomAccessFile oSavedFile; W 1u!&:O
long nPos; 3y,2RernK
'1(6@5tyWk
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public FileAccessI() throws IOException L|L|liWd
{ |sY
this("",0); *[m:4\
} t{QQ;'
;mRZ_^V;
~9xkiu5~
public FileAccessI(String sName,long nPos) throws IOException ~y?Nn8+&f
{ )EQz9
oSavedFile = new RandomAccessFile(sName,"rw"); gwdAf%|f
this.nPos = nPos; \.}ZvM$
oSavedFile.seek(nPos); IUDH"~f
} ~Uey'Xz
ijUu{PG`X
_/'VD!(MV
public synchronized int write(byte[] b,int nStart,int nLen) T?QW$cU!e:
{ @56*r@4:q
int n = -1; lSlZ^.&
try{ QnP?j&
oSavedFile.write(b,nStart,nLen); G+Bk!o
n = nLen; '2hy%
} \#WWJh"W
catch(IOException e) jvAjnh#
{ ;]b4O4C\
e.printStackTrace (); TLp2a<Iy
} a DXaQ
/qMnIo
y:^o._
return n; /]_|uN)Q
} j"hEs(t
S3i p?9
#oFyi @U
} YM6 J:89
FRajo~H
)QRT/, ;c
/* }mzd23^W>P
**SiteInfoBean.java w-2#CX8jY
*/ ExSM=
package NetFox; F\^8k/0
SDV#p];u
LMx/0
public class SiteInfoBean { $v[mIR
DB65vM
,|3_@tUl
private String sSiteURL; //Site's URL ?o$t{AQ
private String sFilePath; //Saved File's Path ?|/K(}
private String sFileName; //Saved File's Name e^3D`GA
private int nSplitter; //Count of Splited Downloading File HA,8O[jon
]jC{o,?s
h#KSKKNW
public SiteInfoBean() bmK
{//nSplitter的缺省值为5 &VA^LS@b
//default value of nSplitter is 5 71Za!3+
this("","","",5); [Eccj`\e g
} U._fb=
> Xh=P%
\#LDX,=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =}kISh
{ mXyN{`q=
sSiteURL= sURL; U;4i&=.!
sFilePath = sPath; "uT2 DY[
sFileName = sName; /RMtCa~
this.nSplitter = nSpiltter; 4v |i\V>M
D!! B4zt
yYYP;N?g4k
} ib#rT{e
@'):rFr@F
3<"j/9;K'
public String getSSiteURL() @&`^#pok
{ HR"clD\{Di
return sSiteURL; ]u!s-=3s
} ZJU %&@
iQ(j_i'+!I
_pZ <
public void setSSiteURL(String value) A[^#8evaK
{ - _8-i1?
sSiteURL = value; *?d\Zcj85[
} q~ ZUtF
A{J?I:
^)Awjj9
public String getSFilePath() Yl>Y.SO
{ (lS[a
return sFilePath; ZD'mwj+K
} `h'l"3l
)^ZC'[93
Hv/5)
public void setSFilePath(String value) fs;\_E[)
{ > ^zNKgSQ
sFilePath = value; 7gN;9pc$
} pZopdEFDK|
m(MQ
ar\|D\0V
public String getSFileName() d/j?.\
{ >'W,8F
return sFileName; cZ|NGkZ
} ga/zt-&
Zv!XNc!"$y
;`LG WT-<F
public void setSFileName(String value) ,$/Ld76U
{ GiX3c^V"1
sFileName = value; MGMJeqvr
} {*F =&D
9x!kvB6
xWXLk )A
public int getNSplitter() @ Do.Wgt
{ O50<h O]l
return nSplitter; _b&26!gl
} qpjZ-[UC
Um\HX6
.=Oww
public void setNSplitter(int nCount) gBhX=2%
{ zJW2F_
nSplitter = nCount; >AX_"Q~
} ZCj1Cz]"l<
} SyI~iW#Y1
Qt{){uE
iTq&h=(n
/* YcX"Z~O6j=
**Utility.java TMY. z
*/ A :KZyd"Z
package NetFox; )Cj1VjAg
M0xhcU_
G.<0^q,
public class Utility { $%\6"P/64
qMVuFwPhi
2"Wq=qy\J
public Utility() q MrM^ ~
{ VFZ?<m
,M?8s2?
8)?&eE'
} n0co* ]X+k
b<4nljbx
//线程睡眠 Qd YYWD
public static void sleep(int nSecond) ;@ixrj0u
{ rZpsC}C'
try{ c}n66qJF5
Thread.sleep(nSecond); OYt_i'Q
} 4hxP`!<
catch(Exception e) zEO~mJzo
{ '+{yg+#/wV
e.printStackTrace (); yp$jLBA
} -hW>1s<
} Xwo+iZ(a
X9|*`h<
//日志 X)hpbHa
public static void log(String sMsg) 1ow,'FztPt
{ %.f%Q?P
System.err.println(sMsg); |wv+g0]Pg^
} ,~38IIS>_
+`gU{e,p
/{hT3ncb
public static void log(int sMsg) [<U=)!Swg
{ Ewr2popK
System.err.println(sMsg); kI!@J6
} ~!mY0odH
} v{|y,h&]a
CSoVB[vS
KzV|::S^
/* C^,baCX
**TestMethod.java "IQYy~ /
*/ >SvS(N{
package NetFox; mMllen
nTo?~=b
IFew3!{\
public class TestMethod { qF$y p>|#
QOUyD;0IW
!2HF|x$
public TestMethod() M0lJyzJ
{ ///xx/weblogic60b2_win.exe 0_ST2I"Ln
try{ \.iejB
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p<'pqf
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5<`83;R9
SiteFileFetch fileFetch = new SiteFileFetch(bean); qzvht4
fileFetch.start(); QeFt WjlqC
} C4ktCN
catch(Exception e){e.printStackTrace ();} qonStIP
uwI"V|g%a&
K]B`&ih
} |pBFmm*
:TP4f ?FA
+{=U!}3|
public static void main(String[] args) $eT[`r
{ ./3/3&6
new TestMethod(); HxW/t7Z(
} l lcq~*zz
} Nb3O>&J
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