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)); rxOvYF
} HE-ErEtGB
for(int i=0;i<nEndPos.length-1;i++) ZQyXzERp
{ (d['f]S+&
nEndPos = nStartPos[i+1]; \q"vC1,9
} n`D-?]*
nEndPos[nEndPos.length-1] = nFileLength; m,Mg
} 2^)_XVX1
} -kb;h F}.
^xq)Q?[{
]'<"qY
//启动子线程 EME}G42KN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |N|[E5Cn
for(int i=0;i<nStartPos.length;i++) - H`,`#{
{ j rg B56LL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OpmPw4?}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OG^#e+
nStartPos,nEndPos,i); K<v:RbU|[1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T+>W(w i
fileSplitterFetch.start(); @Py?.H
} juMHc$d17
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "5"{~3Gw^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HBZtg
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5>-~!Mg1
nEndPos = " + nFileLength); ",]A.,
// fileSplitterFetch[nPos.length-1].start(); j|VX6U
!Hj 7|5
Vg7BK%
//等待子线程结束 {*X|)nr
//int count = 0; < fYcON
//是否结束while循环 fz rH}^
boolean breakWhile = false; :MGIp%3
=/19 -Y:
}ok'd=M
while(!bStop) EV_u8?va
{ +<3e@s&
write_nPos(); ?Skv2!X|
Utility.sleep(500); [@0Hmd7
breakWhile = true; EE*FvI`
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rfOrh^
for(int i=0;i<nStartPos.length;i++) yJ!,>OQ%'
{ <o@__l.
if(!fileSplitterFetch.bDownOver) 8O0]hz
{ NZ-57Ji
breakWhile = false; h_B nQZ\
break; Efu/v<
} |9mGX9q
} C^!~WFy
if(breakWhile) k>#-NPU$
break; u+ 8wBb5!
5yf`3vV|3@
b7HT<$Wg
//count++; UZo[]$"Q`
//if(count>4) 8< z
// siteStop(); 64SRW8AH
} E#\'$@8j
NYPjN9L
I9YMxf>nI
System.err.println("文件下载结束！"); rji<g>GQ
} j#9n.i %h
catch(Exception e){e.printStackTrace ();} z=TuUl@
} v&xhS yZ
zI_pP?4;.q
SA~oGgk=P
//获得文件长度 L/,M@1@R
public long getFileSize() nzKlue
{ j^D/,SW
int nFileLength = -1; 7 ;x to =
try{ QPW+L*2
URL url = new URL(siteInfoBean.getSSiteURL()); sbV_h;<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g8]$BhRIfr
httpConnection.setRequestProperty("User-Agent","NetFox"); BWzo|isv
GX N:=
$~r=I[5'(
int responseCode=httpConnection.getResponseCode(); XW*d\vDun
if(responseCode>=400) 1(/rg
{ ,1il&
processErrorCode(responseCode); )Hqn
return -2; //-2 represent access is error P]4@|u;=6[
} (!T\[6
fKa]F`p_h
&izk$~
String sHeader; 8zpTCae^=7
`'ak/%Krh
$ 3R5p
for(int i=1;;i++) xS_tB)C
{ Y~UWUF%aK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); nW]T-!
//Utility.log(in.readLine()); ?d)FYB
sHeader=httpConnection.getHeaderFieldKey(i); |q 0iX2W
if(sHeader!=null) qO>A6
{ vcSb:('
if(sHeader.equals("Content-Length")) <'O|7. ^^
{ wArzMt}[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d4LH`@SUZ-
break; n&FRjq9y
} -V:7j8
} V/J-zH&
else A~8-{F 31
break; !-8y;,P
} 8-)@q|
} }QJ6"s
catch(IOException e){e.printStackTrace ();} CMYkxU
catch(Exception e){e.printStackTrace ();} `W%R
8b $e)
1Pd2%
Utility.log(nFileLength); l6T5]$
nk+9J#Gs
.7n`]S/
return nFileLength; O_Z
} n ZzGak
IR"=8w#MP
@&2#kO~=
//保存下载信息（文件指针位置） (?z"_\^n/
private void write_nPos() yj mNeZ
{ xOc&n0}%
try{ DC=XPn/V
output = new DataOutputStream(new FileOutputStream(tmpFile)); N)X51;+
output.writeInt(nStartPos.length); ,>3|\4/Q
for(int i=0;i<nStartPos.length;i++) 4M>EQF&
{ Y^'mBM#j
// output.writeLong(nPos); XI5q>cd\Sz
output.writeLong(fileSplitterFetch.nStartPos); e;&fO[2
output.writeLong(fileSplitterFetch.nEndPos); ptTp63+
} BtKbX)R$J
output.close(); Ml+O - 3T
} Ce_l\J8G
catch(IOException e){e.printStackTrace ();} 3$ BYfI3H
catch(Exception e){e.printStackTrace ();} h\*I*I8C
} }z_7?dn/
KOD%>+vG$
|$c~Jq
//读取保存的下载信息（文件指针位置） #mc6;TRZO
private void read_nPos() 4z,n:>oH
{ +qmV|$rmM
try{ j.UO>1{7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); YJBf~0r
int nCount = input.readInt(); mA6Nmq%{ F
nStartPos = new long[nCount]; incUa;
nEndPos = new long[nCount]; .Yxf0y?uv
for(int i=0;i<nStartPos.length;i++) iIU>:)i
{ "ax"k0
nStartPos = input.readLong(); DZV U!J
nEndPos = input.readLong(); oqy}?<SQ
} Q5tx\GE
input.close(); ),f d,
} <O]B'Wc [
catch(IOException e){e.printStackTrace ();} =kn-F T
catch(Exception e){e.printStackTrace ();} r#WAS2.TP
} q#.+P1"U
P6;Cohfh
p}h9>R
private void processErrorCode(int nErrorCode) rTM0[2N
{ YMn_9s7<
System.err.println("Error Code : " + nErrorCode); ;r3|EA35
} \_3#%%z
{iVmae
jLreN#:9
//停止文件下载 PA>su)N$
public void siteStop() /` 4B-Y4M4
{ k_7agW
bStop = true; oCuKmK8
for(int i=0;i<nStartPos.length;i++) G1/
fileSplitterFetch.splitterStop(); <84d Vg
}G1hB#j
XN~r d,MZ%
} j'|`:^ Sy
} rfhvdwwD
//负责部分文件的抓取 4AuJ1Z
**FileSplitterFetch.java <k-hRs2d
*/ Ozs&YZ
package NetFox; >A1;!kGE#
@8V~&yqq
H?j!f$sw
import java.io.*; K_LwYO3
import java.net.*; C07U.nzh
ftbOvG/ I
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public class FileSplitterFetch extends Thread { K"9V8x3Wg
BI0 A0
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String sURL; //File URL F[==vte|
long nStartPos; //File Snippet Start Position +v"%@lC};
long nEndPos; //File Snippet End Position q<wQ/m
int nThreadID; //Thread's ID !<j)D_
boolean bDownOver = false; //Downing is over C\; $RH
boolean bStop = false; //Stop identical ?\![W5uuXG
FileAccessI fileAccessI = null; //File Access interface XGMO~8 3
,SSq4
/S&8%fb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K!_''Fg
{ $#d.@JWi
this.sURL = sURL; pt- 1>Ui
this.nStartPos = nStart; +@5*_n\e`
this.nEndPos = nEnd; o:Q.XWa@MG
nThreadID = id; ?FwjbG<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Zywx.@!
} x>~.cey
=CjN=FM
nwPU{4#l<
public void run() K^+}__;]
{ J9yB'yE8
while(nStartPos < nEndPos && !bStop) ?u_O(eg
{ 9U~sRj=D
TeWpdUCO
!x1ivP
try{ s+XDtO
URL url = new URL(sURL); dNgjM Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); APT/z0X>
httpConnection.setRequestProperty("User-Agent","NetFox"); k;?E,!{
String sProperty = "bytes="+nStartPos+"-"; :pPn)j$
httpConnection.setRequestProperty("RANGE",sProperty); bcC+af0L
Utility.log(sProperty); Ve^rzGU
r&c31k]E
.q9wyVi7GI
InputStream input = httpConnection.getInputStream(); ~Y'j8W
//logResponseHead(httpConnection); >PMLjXK
5WG:m'$$
k>q}: J9V
byte[] b = new byte[1024]; e&J_uG
int nRead; _f@, >l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6b9&V`
{ :T#"bY
nStartPos += fileAccessI.write(b,0,nRead); j9/Ev]im|F
//if(nThreadID == 1) $yg=tWk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &u7oa
} om}jQJ]KH
N(BCe\FV
#Ez+1
Utility.log("Thread " + nThreadID + " is over!"); cWNWgdk,`V
bDownOver = true; Qv>rww]
//nPos = fileAccessI.write (b,0,nRead); IYk^eG:;
} ZP^7`q)6
catch(Exception e){e.printStackTrace ();} ;IX*4E'4s
} <{UjO
} `Aa*}1
zaoC
Wx-vWWx*Q
//打印回应的头信息 wx%TQ!
public void logResponseHead(HttpURLConnection con) -C<Ni
{ W^AY:#eX~Q
for(int i=1;;i++) \w+a Q?e_
{ nH% 1lD?:
String header=con.getHeaderFieldKey(i); y OLqIvN
if(header!=null) K7N.gT*4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a5xmIp@6
Utility.log(header+" : "+con.getHeaderField(header)); q^k]e{PD
else @ME .
break; Z-B b,8
} K{x FhdW
} +Jv*u8T'
C^hCT
aR~Od Ys
public void splitterStop() <OC|z3na_
{ .&Ok53]b
bStop = true; /)E'%/"A
} duk:: |{F
KGoHn6jM
,Y3wXmG
} ,dO$R.h
X0"f>.Lg
hpVu
/* Qo;#}%}^^
**FileAccess.java )Mj $/
*//文件访问(定位，写) ';0NWFP
package NetFox; J\V.J/
import java.io.*; 3Ta<7tEM
Cq-#|+zr
O#5ll2?
public class FileAccessI implements Serializable{ , JUP
WgK|r~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 XgmblNp1
RandomAccessFile oSavedFile; 5Si\hk:o
long nPos; Vt!<.8&`
_noQk3N
\"u3x.!
public FileAccessI() throws IOException f!"Y"g:@E
{ +#d}3^_]
this("",0); +e6c4Tw/
} 3]9twfF 'J
}lzQMT
>`@yh-'r
public FileAccessI(String sName,long nPos) throws IOException fx783
{ k-LT'>CWl
oSavedFile = new RandomAccessFile(sName,"rw"); V^U1o[`
this.nPos = nPos; i!=28|_
oSavedFile.seek(nPos); ?98]\pI
} Dxwv\+7]
OLdD3OI
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public synchronized int write(byte[] b,int nStart,int nLen) J '^xDIZX
{ *KXg;777
int n = -1; ", :Ta|
try{ M:~/e8Xv
oSavedFile.write(b,nStart,nLen); ;5.o;|w?!
n = nLen; 6!3Jr
} I:qfB2tL)O
catch(IOException e) o,sw[
{ T"GuE[?a
e.printStackTrace (); >Lo!8Hen
} dWI.t1`i
OZ$"P<X_"
]%y~cq
return n; z]YP
} -*K!JC-
`>q|_w\e
B az:N6u
} s\`Vr;R:|
|;-,(509
_0rHxh7}q
/* $VrKoL\ScA
**SiteInfoBean.java 28j=q-9Z
*/ `37GVo4
package NetFox; /I'n]
?]=fC{Rh
9o7d3ir)
public class SiteInfoBean { #f'(8JjY
Y"uFlHN&i
$J |oVVct
private String sSiteURL; //Site's URL Dk'EKT-
private String sFilePath; //Saved File's Path a*pZcv<
private String sFileName; //Saved File's Name %acy%Sy
private int nSplitter; //Count of Splited Downloading File @J~y_J{
G@)I
NS l$5E
public SiteInfoBean() 5g-apod
{//nSplitter的缺省值为5 %}=$HwN)
//default value of nSplitter is 5 I~R<}volu
this("","","",5); wjmZ`UMz
} {1GW,T!#
%;0w2W
.'SXRrn&:C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3_atv'I
{ ~PNO|]8j
sSiteURL= sURL; ."Yub];H
sFilePath = sPath; kCR)k=*
sFileName = sName; FGOa!G
this.nSplitter = nSpiltter; ]kmOX
gkpNT)
bH41#B
} oPNYCE
/S;o2\
xaerMr
public String getSSiteURL() a{h(BI^~
{ >:]fN61#
return sSiteURL; \QUvImT
} ,h2q37
ru`;cXa,
T^a {#B
public void setSSiteURL(String value) !v2,lH
{ hh"0z]
sSiteURL = value; LeW.uh3.
} qD\%8l.]Z
lq@Vb{Z
AEwb'
public String getSFilePath() {K'SOhH4?
{ 8mA6l0
return sFilePath; |4Ix2GD
} 04;y%~,}U/
ABV\:u
E|9LUPcb
public void setSFilePath(String value) xgR*j
{ 6\,^MI
sFilePath = value; ) WIlj
} IQ{Xj3;?y
V8&/O)}o
MatC2-aV1
public String getSFileName() bT-G<h*M
{ W7A'5
return sFileName; 4Sg!NPuu7&
} l7{hq}@;cC
+>qBK}`
)O- x1U
public void setSFileName(String value) %FFw!eVi
{ @\l> <R9V
sFileName = value; Re1@2a>
} w=e,gNO
N0RFPEQ~
F'CUkVC0~P
public int getNSplitter() >2syF{`j
{ GIVs)~/Eq
return nSplitter; 8 (^2
} CES FkAj~
!T,7
24N,Bo 3
public void setNSplitter(int nCount) #>'1oC{
{ H[N&Wiq/|
nSplitter = nCount; pjj 5
} G^mk<pH
} 'v|2}T*
^RWt
*vAOUqX`x
/* g&0GO:F`
**Utility.java ]|`gTD6
*/ )Elr8XLw
package NetFox; 9jPb-I-
/#G"'U/
{t/!a0\HS
public class Utility { <M'IRf/D
PYHm6'5BtB
"(efd~.]
public Utility() x#8=drh.:C
{ 4\OELU
Ok`U*j
,IJNuu\
} Ee|+uQ981>
_SP u`=~K
//线程睡眠 d7^XP
public static void sleep(int nSecond) 8e\v5K9
{ hYd8}BvA
try{ 6$6NVq
Thread.sleep(nSecond); ESrWRO f9
} X3m?zQbhv
catch(Exception e) *Ra")(RnDK
{ n&C9f9S
e.printStackTrace (); Y!7P>?)`,X
} k(qQvn
} Wq9s[)F"Z
}"&(sYQ*`
//日志 Ro1' L1:
public static void log(String sMsg) ^,KR0
{ FoG<$9
System.err.println(sMsg); xY'g7<})$
} ,xh9,EpBk
&vF"I'V
)(L&+DDy
public static void log(int sMsg) <@vE3v;
{ ;ZqFrHI M`
System.err.println(sMsg); -.*\J|S@g
} M<p)@p
} :9h8q"T
Gj^bz'2
|wb7`6g
/* Np-D:G
**TestMethod.java ^r& {V"l]
*/ ?0(B;[xEJ
package NetFox; cY"^3Ot%^
*tO<wp&
B)Q'a3d#
public class TestMethod { a,4g`?
@iP6N
Ur-^X(nL
public TestMethod() ;p_X7N
{ ///xx/weblogic60b2_win.exe !xc7~D@om(
try{ 0/gcSW b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QLUe{@ivc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $($SQZK&
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6'%]6"&M4
fileFetch.start(); e"CLhaT
} UJH{vjIv
catch(Exception e){e.printStackTrace ();} P8VU&b\
`l+SJLyJ%
LXfiSM{o
} bvx:R ~E$
%pp+V1FH
~?&ijhZ
public static void main(String[] args) G'py)C5;
{ flB,_
new TestMethod(); o/zCXZnw#
} X2uX+}h*tA
} [dJ\|=
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