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)); 7__?1n~{
} qb1[-H
for(int i=0;i<nEndPos.length-1;i++) *]RCfHo\=
{ a#4 'X*
nEndPos = nStartPos[i+1]; SebJ}P1x
} 2%(RB4+
nEndPos[nEndPos.length-1] = nFileLength; *oU-V#
} Y]>Qu f.!
} O)Mf/P'
"/}cV5=Z
J{bNx8.&
//启动子线程 #Bgq]6G2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; KK4"H]!.
for(int i=0;i<nStartPos.length;i++) Kk_h&by?
{ {r2fIj~V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8}(ul
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aj)?P
nStartPos,nEndPos,i); @CU~3Md*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,%%}d9
fileSplitterFetch.start(); '4}c1F1T_
} I~.d/!>Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]J* y`jn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /)E'%/"A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xMAb=87_
nEndPos = " + nFileLength); t=Um@;wh
// fileSplitterFetch[nPos.length-1].start(); q=40l
p3YF
1_z6O!rx
//等待子线程结束 SS/t8Y4W
//int count = 0; .A2u7*h&
//是否结束while循环 t@O4!mFH
boolean breakWhile = false; ~8 w(M
$ZOKB9QccC
}.R].4gT
while(!bStop) `bF]O"
{ :xP$iEA`G
write_nPos(); 11Hf)]M
Utility.sleep(500); tSvklI
breakWhile = true; U.B=%S
t|Ipxk.)
p!~{<s]
for(int i=0;i<nStartPos.length;i++) "=BO,see9
{ Y4B<]C4
if(!fileSplitterFetch.bDownOver) J|BZ{T}d
{ XN=Cq*3}
breakWhile = false; KZxA\,Y'5
break; hIr$^%
} r 7mg>3
} K{s%h0
if(breakWhile) 2i@t;h2E
break; !&Z,ev
U5z}i^8a
{)vue0 vP
//count++; Q$(0Nx<
//if(count>4) n*oa J<o%
// siteStop(); A'\jaB
} <XHS@|
"n3i(sZ
;5.o;|w?!
System.err.println("文件下载结束！"); 6!3Jr
} I:qfB2tL)O
catch(Exception e){e.printStackTrace ();} n6a*|rE
} 426)H_wx
8zRb)B+
%ycCNS
//获得文件长度 Z{w{bf1&A
public long getFileSize() "k${5wk#Fl
{ [?$|
int nFileLength = -1; Gkr^uXNg#
try{ ?"aj&,q+
URL url = new URL(siteInfoBean.getSSiteURL()); iZy`5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L8~nx}UP5
httpConnection.setRequestProperty("User-Agent","NetFox"); O&:0mpRZ
VhAZncw
w$5N6
int responseCode=httpConnection.getResponseCode(); {xC CUU
if(responseCode>=400) 'ZHu=UT7_
{ WLAJqmC]
processErrorCode(responseCode); >Ufjmm${
return -2; //-2 represent access is error ; -RhI_
} W].P(A>m
,Dz2cR6
x,Cc$C~YP
String sHeader; l}DCK
IKK<D'6
K+` Vn
for(int i=1;;i++) :);]E-ch
{ NS l$5E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5g-apod
//Utility.log(in.readLine()); vl@t4\@3
sHeader=httpConnection.getHeaderFieldKey(i); 1]@}+H
if(sHeader!=null) Zw5\{Z0
{ %;0w2W
if(sHeader.equals("Content-Length")) fxDY:l
{ 3_atv'I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }eX_p6bBw
break; X*~NE\
} @Y>3-,o,S
} +fhyw{
else |7Q8WjCQ{m
break; R0<ka[+
} n;"4`6L~
} z#!xqIg0
catch(IOException e){e.printStackTrace ();} 7[-jr;v
catch(Exception e){e.printStackTrace ();} v.1= TBh
(oxe\Qk
'D-#,X C
Utility.log(nFileLength); yvxC/Jo4
6QRfju'
=3=KoH/'
return nFileLength; zJMKgw,i*
} l\^q7cXG
LeW.uh3.
qD\%8l.]Z
//保存下载信息（文件指针位置） (nrrzOax
private void write_nPos() co3H=#2a
{ \i-jME(sN
try{ =tcPYYD
output = new DataOutputStream(new FileOutputStream(tmpFile)); *eXO?6f%s^
output.writeInt(nStartPos.length); ^c]Sl
for(int i=0;i<nStartPos.length;i++) L\og`L)5\
{ B>?Y("E
// output.writeLong(nPos); &Jj> jCg
output.writeLong(fileSplitterFetch.nStartPos); E|9LUPcb
output.writeLong(fileSplitterFetch.nEndPos); YeJ95\jf
} g]xZ^M+
output.close(); 6\,^MI
} ) WIlj
catch(IOException e){e.printStackTrace ();} FbM5Bqv
catch(Exception e){e.printStackTrace ();} ^@L[0Z`
} L1QQU
]@J}f}Mjo
@`.u"@
//读取保存的下载信息（文件指针位置） !BEOeq@2.
private void read_nPos() U>;itHW/
{ ?<frU ,{
try{ T *t$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /^[)JbgB
int nCount = input.readInt(); H>XbqIkL@
nStartPos = new long[nCount]; %Z{J=
nEndPos = new long[nCount]; ~v>w%]
for(int i=0;i<nStartPos.length;i++) e( ^9fg_SG
{ (&MSP
nStartPos = input.readLong(); :e@JESlLf
nEndPos = input.readLong(); 8VcAtrx_
} R~*Y@_oD
input.close(); r-YQsu&
} Vd<= y
catch(IOException e){e.printStackTrace ();} [bPE?_a,
catch(Exception e){e.printStackTrace ();} J-PzIFWd
} <vt^=QA'
)dL?B9d:
rF0zGNH
private void processErrorCode(int nErrorCode) ($(1KE
{ *vAOUqX`x
System.err.println("Error Code : " + nErrorCode); g&0GO:F`
} 4_.k Q"'DH
J|FyY)_
?XOeMI
//停止文件下载 T%a]3
public void siteStop() j|G-9E
{ oZCi_g 5i
bStop = true; g41Lh3dj
for(int i=0;i<nStartPos.length;i++) gy =`cMS@
fileSplitterFetch.splitterStop(); `4EOy:a
z~ u@N9M
!RcAJs'
} T (2,iG8
} y]jh*KD[
//负责部分文件的抓取 '*,4F'
**FileSplitterFetch.java j[U0,]
*/ c?R.SBr,'
package NetFox; _TPo=}Z
jATU b-
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import java.io.*; 6$6NVq
import java.net.*; ESrWRO f9
rFy9K4D
Na~_=3+a
public class FileSplitterFetch extends Thread { wO!hVm,Ta
Y!7P>?)`,X
k(qQvn
String sURL; //File URL 2mlE;.}8
long nStartPos; //File Snippet Start Position C(0Iv[~y/
long nEndPos; //File Snippet End Position =hs@W)-O
int nThreadID; //Thread's ID PRz oLzr
boolean bDownOver = false; //Downing is over %xZ.+Ff%
boolean bStop = false; //Stop identical F{"%ey">
FileAccessI fileAccessI = null; //File Access interface /MU<)[*Ro
>(*jbL]p
#wjBMR%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .FXQ,7mZ-
{ f.P( {PN
this.sURL = sURL; w%_BX3GTO
this.nStartPos = nStart; ,?d%&3z<a
this.nEndPos = nEnd; 8_,ZJ9l;
nThreadID = id; V[xy9L[#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _(z"l"l=$
} R]Yhuo9,&n
Azle ;\l`
}1W$9\%
public void run() y*(YZzF
{ ]s -6GT
while(nStartPos < nEndPos && !bStop) K`X2N
{ ww,c)$
4By-+C*
_[phs06A
try{ eLYFd,?9
URL url = new URL(sURL); jF;4 8g@^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OWjZ)f/
httpConnection.setRequestProperty("User-Agent","NetFox"); 8 KkpXaz
String sProperty = "bytes="+nStartPos+"-"; Vx*q'~4y!|
httpConnection.setRequestProperty("RANGE",sProperty); h^0mjdSp,
Utility.log(sProperty); 4AM*KI
!qpu /
P8VU&b\
InputStream input = httpConnection.getInputStream(); `l+SJLyJ%
//logResponseHead(httpConnection); LXfiSM{o
Ww(_EW
<di_2hN
byte[] b = new byte[1024]; i`SF<)M(
int nRead; 31*6 ;(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JJ~?ON.H
{ \+uqP:Ty
nStartPos += fileAccessI.write(b,0,nRead); biG9?
//if(nThreadID == 1) 84[^#ke
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r9Z/y*q
} u7=[~l&L
'JMa2/7CG
$aA.d^
Utility.log("Thread " + nThreadID + " is over!"); 1;P\mff3Y
bDownOver = true; `aUp&8{
//nPos = fileAccessI.write (b,0,nRead); <C$<(Dw5
} 4PWr;&
catch(Exception e){e.printStackTrace ();} =vc5,
} 6\3k0z
} ]1&9~TL
RF)B4D-W
88>Uu!M=f
//打印回应的头信息 1,j9(m2
public void logResponseHead(HttpURLConnection con) {K9E% ,w
{ %jxuH+L
for(int i=1;;i++) V8yX7yx
{ a+/|O*>#
String header=con.getHeaderFieldKey(i); I{zE73
if(header!=null) AuTplO0_rE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k^pu1g=6I
Utility.log(header+" : "+con.getHeaderField(header)); j>*SJtq7
else 6Qb)Uq3}]
break; \=7=>x_
} %20-^&zZ
} V@:=}*E
M@g gLW
f hG2
public void splitterStop() RuNH (>Eb
{ LH#LBjOZk
bStop = true; WWcm(q=
} 2w|u)ow)
KN:dm!A
gVU\^KN]
} mzxvfXSF
tgtoK|.
-0SuREn
/* XOg(k(&T
**FileAccess.java 0~b6wuFl
*//文件访问(定位，写) ]8>UII,US
package NetFox; k^5Rf
import java.io.*; @Q\$dneY
2Lekckgv
\G=R hx f
public class FileAccessI implements Serializable{ (l8r>V
V1nZ M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SE9u2Jk
RandomAccessFile oSavedFile; $v<hW A]>
long nPos; Usf"K*A
csX*XiDWm
G\>\VA
public FileAccessI() throws IOException b/,!J]W
{ i?_D]BY4
this("",0); <<On*#80w
} ;=VK_3"
a^\- }4yR
-)a_ub
public FileAccessI(String sName,long nPos) throws IOException QjjJtKz
{ sJI-
oSavedFile = new RandomAccessFile(sName,"rw"); 2PP-0 E
this.nPos = nPos; z?uQlm*We
oSavedFile.seek(nPos); %{~mk[d3
} b|ksMB>)
&Wv`AoV
=PKt09b^
public synchronized int write(byte[] b,int nStart,int nLen) <x0uO
{ @7l=+`.i
int n = -1; -=Eq/su%
try{ &>zy_)
oSavedFile.write(b,nStart,nLen); ?fa,[r|G
n = nLen; l`FR.)2h
} aEFe!_QY
catch(IOException e) w HHF=Q
{ QV'3O|
e.printStackTrace (); a[P>SqT4`
} ;TV'PJ
%<J(lC9,C
Kjn&
return n; \B>[je-d
} )_Xxk_
t`8e#n 9
\|pK Z6*s
} wO_pcNYZ8
A.$VM#
RZ)vU'@kx
/* 1f@U:<:
**SiteInfoBean.java d%_78nOh"
*/ $-fjrQ
package NetFox; {F(-s"1;xO
$O~F>.*
K+7yUF8XP
public class SiteInfoBean { ,LW(mdIe(
s9_`Wrg?
/[nZ#zj!3
private String sSiteURL; //Site's URL cEdz;kbUM
private String sFilePath; //Saved File's Path *<.WL"Qhl
private String sFileName; //Saved File's Name Yn$>QS 4
private int nSplitter; //Count of Splited Downloading File SD|4ybK>d
c5iormb"#
m.HX2(&\3
public SiteInfoBean() -@ UN]K
{//nSplitter的缺省值为5 J]|6l/i
//default value of nSplitter is 5 K.#,O+-Kg`
this("","","",5); /UaNYv/
} C6D=>%uY
liCCc;&B;
RQ*|+~H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !4 4mT'Y
{ 7SA-OFM
sSiteURL= sURL; TRySl5jx@
sFilePath = sPath; :_fjml/
sFileName = sName; p;n3`aVh
this.nSplitter = nSpiltter; XC7Ty'#"KX
n $O.>
+9 16ZPk
} qUEd E`B
iJdrY6qd
JI+KS
public String getSSiteURL() ^:cb $9F
{ wv7p,9Z[
return sSiteURL; OXIu>jF
} H)j[eZP
_>jrlIfc
;9p#xW6
public void setSSiteURL(String value) =q"w2b&
{ ]uStn
sSiteURL = value; U!a!|s>
} [U%ym{be^
je- ,S>U
M!&_qj&N,
public String getSFilePath() HIPcZ!p
{ IFC%%It5,
return sFilePath; 0.J1!RIK/
} {FV,j.D
dJ%wVY0z=
VVI8)h8
public void setSFilePath(String value) fW5"4,
{ !7mvyc!'!
sFilePath = value; k\+y4F8$x
} u@=+#q~/P
Q*09E
_XY`UZ
public String getSFileName() <K DH
{ Nl=m'4@`
return sFileName; ]=?X*,'
} PS_3Oq)
1qm/{>a-
l5ZADK4
public void setSFileName(String value) 097Fvt=#
{ #L@} .Giz
sFileName = value; pW*{Mx
} vi[#?;pkF
g{g`YvLu^
gZ`32fB%
public int getNSplitter() Gsds!z$
{ q:`77
return nSplitter; pgz:F#>
} klK-,J
#;\L,a|>*
p|&ZJ@3
public void setNSplitter(int nCount) vHs>ba$"
{ 0%;N9\
nSplitter = nCount; iX8h2l
} a' IX yj
} ou<S)_|Iu
Fe_::NVvk
jgo e^f
/* 6)=](VmNL`
**Utility.java ffmG~$Yh_
*/ 8N=%X-R%
package NetFox; H$NP1^5!
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]Y_{P~ZX
public class Utility { \GijNn9ah
-:)DX++
Nk lz_]
public Utility() 4o1Q7
{ ( GFgt_
:3111}>c
i&A{L}eCr:
} |Hx%f
K(-G: |
//线程睡眠 fkdf~Vb
public static void sleep(int nSecond) Y5nz?a
{ #5'c\\?Q
try{ 8q_1(& O
Thread.sleep(nSecond); lTa1pp Zw
} qg^(w fI
catch(Exception e) d4jVdOq2
{ ry$tK"v/
e.printStackTrace (); Hfh@<'NL]
} [GtcaX{Zz
} Oq #o1>
<'r0r/0g?
//日志 Dl0/-=L
public static void log(String sMsg) NzjMk4t
{ WuBmdjZ
System.err.println(sMsg); "sFW~Y
} 4 hL`=[AB
"V:
*,E;
public static void log(int sMsg) k%{ l4
{ K5P Gi#
System.err.println(sMsg); JzHqNUn*M
} Z1VC5*K
} W;^Rx.W
G1kDM.L
o^6jyb!j
/* &J\B\`
**TestMethod.java 3Z_t%J5QZ$
*/ [_j6cj]
package NetFox; :9(3h"
`2>XH:+7F
`>%-
public class TestMethod { 7;^((.]ln
7*+Km'=M
YkSuwx@5_q
public TestMethod() ZH\0=l)
{ ///xx/weblogic60b2_win.exe uK"^*NEC';
try{ -oU@D
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xcHen/4X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); DYc.to-
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9~=gwP
fileFetch.start(); 4S'[\ZJO
} E3y6c)<
catch(Exception e){e.printStackTrace ();} U?^OD
lco~X DI
^SEc./$
} IDj_l+?c
p`\3if'
>H$;Z$o*(
public static void main(String[] args) A_@I_V$
{ FH4u$g+
new TestMethod(); a|U}Ammr
} I=U+GY:
} l(gJLjTH%
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