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)); V(&L
} `LkrG9KV{
for(int i=0;i<nEndPos.length-1;i++) Dmh$@Uu#F
{ 1mmL`M1
nEndPos = nStartPos[i+1]; -gs I:-Xo
} o-8{C0>:
nEndPos[nEndPos.length-1] = nFileLength; gNZwD6GMe?
} 3WwS+6R
} >j?5?J"
;dzy5o3
!BoGSI
//启动子线程 \g34YY^L3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )g:5}+
for(int i=0;i<nStartPos.length;i++) mV^w|x
{ M XG>|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s-CAo~,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iWt%Boyi
nStartPos,nEndPos,i); [(n5-#1S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q,NnB{R
fileSplitterFetch.start(); \Tz|COG5h\
} `:C1Wo^<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n5QO'Jr%[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z|qI[uiO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V>Jr4z
nEndPos = " + nFileLength); &;$uU
// fileSplitterFetch[nPos.length-1].start(); 2U./ Yfk\
.B`$hxl*0c
S|=)^$:
//等待子线程结束 ,l&?%H9q
//int count = 0; P@O_MT
//是否结束while循环 s,_+5ukv
boolean breakWhile = false; K28L(4)
I$"Z\c8;
.F ?ww}2p]
while(!bStop) #eJfwc1JY
{ ?xaUWD
write_nPos(); 6m&GN4Ca
Utility.sleep(500); kQ=bd{a6
breakWhile = true; 12^uu)6Xm,
<Y)14w%
>v,X:B?+FL
for(int i=0;i<nStartPos.length;i++) od!44p]
{ ranem0KQ)]
if(!fileSplitterFetch.bDownOver) sPK]:iC
{ 1sXCu|\q
breakWhile = false; RC7F/|w.z
break; Xq1#rK(
} 5]i#l3")
} IgbuMEfL
if(breakWhile) 'fn}I0Vc
break; [],[LkS
EeYL~ORdi
le5@WG/x
//count++; URVW5c
//if(count>4) >)K3
// siteStop(); 8$-MUF,
} 6Jgl"Jw8
rRevyTs
'wPX.h?
System.err.println("文件下载结束！"); ^$oa`B^2JM
} Apu-9|oP
catch(Exception e){e.printStackTrace ();} ]:f.="
} gxhp7c182
'N{1b_v?
6O/L~Z*t
//获得文件长度 ~;(\a@ _
public long getFileSize() tM5(&cQ!d
{ z 4}"oQk:r
int nFileLength = -1; 7O)ATb#up
try{ }6l:'nW
URL url = new URL(siteInfoBean.getSSiteURL()); MQ =x:p{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z&^vEQ
httpConnection.setRequestProperty("User-Agent","NetFox"); 7Ydqg&
N)(m^M(~0
p7+{xXf
int responseCode=httpConnection.getResponseCode(); pKLcg"{[F
if(responseCode>=400) W<<G 'Km
{ `pbCPa{Y
processErrorCode(responseCode); D0#U*tq;
return -2; //-2 represent access is error k[mp(
} $U,]c
jpi,BVTI-X
:/6:&7s
String sHeader; p cD}SY
*`OXgkQ
ydD:6bBX
for(int i=1;;i++) ]9@4P$I
{ Rs<S}oeLn
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EW]DzL3
//Utility.log(in.readLine()); >0kL9_9{
sHeader=httpConnection.getHeaderFieldKey(i); <2*+Y|Lk2
if(sHeader!=null) 23LG)or.JC
{ ,pcyU\68v
if(sHeader.equals("Content-Length")) ,JH*l:7
{ @{V`g8P>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {X,-T&
break; Rq15AR
} |%4nU#GoB
} h(2{+Y+
else TFbc@rfB
break; n}NUe`E_h
} a\-5tYo`u
} PM*lnd#J
catch(IOException e){e.printStackTrace ();} !o'a]8
catch(Exception e){e.printStackTrace ();} h9Sf
>o"s1* {
v*excl~
Utility.log(nFileLength); KXTk.\c
hpOY&7QUTD
G} [$M"}
return nFileLength; )cN=/i
} 1 =?pL$+G
;Qd'G7+
H"+|n2E^
//保存下载信息（文件指针位置） /_<_X 7
private void write_nPos() ,9|7{j|u
{ v'L"sgW6I
try{ !h&h;m/c
output = new DataOutputStream(new FileOutputStream(tmpFile)); jhG6,;1zMI
output.writeInt(nStartPos.length); 2aivc,m{r
for(int i=0;i<nStartPos.length;i++) pC4uar
{ ]mBlXE:Z
// output.writeLong(nPos); #)D$\0ag
output.writeLong(fileSplitterFetch.nStartPos); BI2'NN\
output.writeLong(fileSplitterFetch.nEndPos); Q-_;.xy#4
} a&)$s;
output.close(); ]$K58C
} -b%' K}.C
catch(IOException e){e.printStackTrace ();} I-s$U T[p
catch(Exception e){e.printStackTrace ();} e,vgD kI;
} #;2mP6a[
:@~3wD[y
OwC{ Ad{
//读取保存的下载信息（文件指针位置） 'e))i#/VF
private void read_nPos() TFc/`
{ C1HNcfa7
try{ >taT V_,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R{4[.
int nCount = input.readInt(); wj$3L3
nStartPos = new long[nCount]; yaj1nq!*"
nEndPos = new long[nCount]; w2"]%WS%
for(int i=0;i<nStartPos.length;i++) A}!D&s&UH
{ i/N68
nStartPos = input.readLong(); GB>h8yXH
nEndPos = input.readLong(); +],2smd@N
} eF8um$t9
input.close(); 1 xrmmK
} G* mLb1
catch(IOException e){e.printStackTrace ();} c_?!V
catch(Exception e){e.printStackTrace ();} S r7EcT-
} (>D{"}
;f3))x
#"-w;T%b
private void processErrorCode(int nErrorCode) U,/9fzgd
{ ;hDIoSz
System.err.println("Error Code : " + nErrorCode); XK l3B=h
} 9OF(UFgS
Th])jQ*
Y%rC\Ij/i
//停止文件下载 MM+nE_9lV
public void siteStop() ~xZ)btf
{ ?IG+U TI
bStop = true; 4pu>f.
for(int i=0;i<nStartPos.length;i++) /i~n**HeF?
fileSplitterFetch.splitterStop(); +fF4]WFP
h8SK8sK<
cMt , 80
} .9bP8u2B{
} ]s_BOt
//负责部分文件的抓取 Cvs4dd%)i
**FileSplitterFetch.java Xo4K!U>TzZ
*/ fl9J
package NetFox; ;#D:S6 L
%}~Ncn_r
`_e1LEH
import java.io.*; b|h`v
import java.net.*; hzk]kM/OC
DOo34l6#
Yv;18j*<
public class FileSplitterFetch extends Thread { l< |)LDq~
r+l3J>:K
q(@hYp#O"3
String sURL; //File URL ;(Qm<JAa
long nStartPos; //File Snippet Start Position 0j~C6vp
long nEndPos; //File Snippet End Position _EZrZB
int nThreadID; //Thread's ID V@>s]]HMq#
boolean bDownOver = false; //Downing is over `Axn
boolean bStop = false; //Stop identical G5x%:,n
FileAccessI fileAccessI = null; //File Access interface b!|c:mE9|
Q[F$6m%o
zwX1&rN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \\Huk*Jn{
{ xqzdXL}
this.sURL = sURL; PAXdIh[]
this.nStartPos = nStart; au1(.(
this.nEndPos = nEnd; C@ z^{Z+
nThreadID = id; ^RS`q+g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |N>TPK&Xt
} 5SY(:!
VJ(#FA2
A[oxG;9xi
public void run() =:=uV0jX\
{ aV8]?E5G
while(nStartPos < nEndPos && !bStop) AUAJMS!m
{ V5LzUg]
AA,n.;zy<
ygp NMq#?X
try{ NvfQa6?;
URL url = new URL(sURL); 0l ]K%5#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >H?{=H+/#
httpConnection.setRequestProperty("User-Agent","NetFox"); rOy-6og
String sProperty = "bytes="+nStartPos+"-"; 6jtnH'E/
httpConnection.setRequestProperty("RANGE",sProperty); +lqX;*a=N
Utility.log(sProperty); ;/Dp
@(A[H^E
S2fBZ=V8
InputStream input = httpConnection.getInputStream(); 5eWGX
//logResponseHead(httpConnection); A|d(5{:N
Lm}:`
Fn!kest
byte[] b = new byte[1024]; WY%'ps_]<
int nRead; =sW(2Im
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e'z[JG=
{ }A`4ae=
nStartPos += fileAccessI.write(b,0,nRead); M1T)e9k=x
//if(nThreadID == 1) mMvt#+O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B@Q Ate7
} LN?W~^gsR
uN1O(s
u>.qhtm[
Utility.log("Thread " + nThreadID + " is over!"); qG%'Lt
bDownOver = true; %A dE5HI-
//nPos = fileAccessI.write (b,0,nRead); R"=pAO.4l
} ^i^/d#
catch(Exception e){e.printStackTrace ();} 0Y9\,y_
} Iw$7f kq
} V1j5jjck
qJN2\e2~f
/r Hd9^Y
//打印回应的头信息 Hb;#aXHSd
public void logResponseHead(HttpURLConnection con) *.J)7~(P
{ #yk m
for(int i=1;;i++) IOsitMOX:
{ +idj,J|
String header=con.getHeaderFieldKey(i); *s9 +
if(header!=null) 'lym^^MjL+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yb#NB)+E@
Utility.log(header+" : "+con.getHeaderField(header)); zR+EJFf
else $!x8XpR8s
break; x\Bl^1&
} q(J3fjY)
} 39QAj&
C0X_t
8rXu^
public void splitterStop() A-&C.g
{ io$!z=W
bStop = true; r-+.Ax4L"
} z17x%jXy
:U>o;
Dxu2rz!li-
} uf (`I
G:QaWqUb
@""aNKA^r>
/* ;k<g#She
**FileAccess.java @O/-~,E68
*//文件访问(定位，写) %W=S*"e-
package NetFox; d([NU;
import java.io.*; ;5A
JZP>`c21y]
t%wC~1
public class FileAccessI implements Serializable{ 3eqnc),Z
)Ab!R:4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vcnUb$%
RandomAccessFile oSavedFile; y8uB>z+#+;
long nPos; pzP~,cdf
iXt >!f*
gf^"sfNk
public FileAccessI() throws IOException @54D<Lj
{ MMglo3
this("",0); jiMI&cl
} & Me%ZM0
*4;MO2g
VQO6!ToKY
public FileAccessI(String sName,long nPos) throws IOException *wcb5p
{ o[W7'1O
oSavedFile = new RandomAccessFile(sName,"rw"); vd>X4e^j
this.nPos = nPos; ]?p&sI4
oSavedFile.seek(nPos); 7yLO<o?9w
} j_VTa/
xJ)hGPrAl
y|1,h}H^n
public synchronized int write(byte[] b,int nStart,int nLen) ({g7{tUy^H
{ Gk0f#;
int n = -1; #8G(r9
try{ w:P$S
oSavedFile.write(b,nStart,nLen); y{ReQn3>y
n = nLen; GtRc7,
} r7r>1W%4
catch(IOException e) U)%gzXTZ%
{ 2B{~"<
e.printStackTrace (); tY^MP5*
} <J4|FOz!=
L$^ya%2
7RQ.oee
return n; `VT[YhO#}
} e$M \HPc
ORhe?E]
?+)O4?#
} D/C)Rrq"a
M[N$N`9
B:om61Dn
/* 6vySOVMj
**SiteInfoBean.java |[/[*hDZ9
*/ Z&gM7Zo8
package NetFox; L|Zja*
'`$z!rA
c=iv\hn
public class SiteInfoBean { 7jIye8Zi8
<RfPd+</
}=CL/JHz
private String sSiteURL; //Site's URL ?z>7&
private String sFilePath; //Saved File's Path og<mFbqkq7
private String sFileName; //Saved File's Name C 7)w8y
private int nSplitter; //Count of Splited Downloading File 1Uzsw
v|:2U8YREf
:feU
public SiteInfoBean() XLe8]y=
{//nSplitter的缺省值为5 <u2rb6
//default value of nSplitter is 5 `wRQ-<Y
this("","","",5); ^a&-GhX;
} 2JNO@
&eYnO~$!
O(U'G|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) tJ>|t hk
{ II;fBcXF
sSiteURL= sURL; / 4P+
sFilePath = sPath; :td#zM
sFileName = sName; w8$rt
this.nSplitter = nSpiltter; R4+Gmx1
G9y 0;br
k*)O]M<,
} ^.5`jdk
$e66jV
Y0`@$d&n
public String getSSiteURL() nA:\G":\y
{ GRV#f06
return sSiteURL; i;4|UeUl
} Q@B--Omfh
9aYDi)
?+{=>{1
public void setSSiteURL(String value) 3n{'}SYyz
{ DU9A3Z
sSiteURL = value; |BrD:+
} axT-
L@> +iZSO
H]v"_!(\
public String getSFilePath() (ATvH_Z
{ Y@WCp
return sFilePath; ?U~}uG^
} q}Wd`>VDR
lLD-QO}/
nNe`?TS?f
public void setSFilePath(String value) B{IYVviiP
{ 7gIK+1`
sFilePath = value; C~\/FrO?
} @R+bR<}]
;DWtCtD
Yv0;UKd
public String getSFileName() qkX}pQkG)h
{ DtBIDU]
return sFileName; }q0lbwYlb
} f@@2@# 5B
CRsgR)
F$a?} }
public void setSFileName(String value) V,>_L
{ qta^i819
sFileName = value; /+pPcK
} C4V#qhj
ni @Mqb
CV<@Rgoa
public int getNSplitter() 6*@\Qsp615
{ "52nT
return nSplitter; mG,%f"b0
} b}P5*}$:9"
cp|&&q
![O@{/
public void setNSplitter(int nCount) IEb"tsel
{ K*&?+_v :
nSplitter = nCount; F^iv1b
} F_Q,j]0
} \L14rQ t
H]:z:AAvX
Bsm>^zZ`YU
/* $)OUOv
**Utility.java h'8w<n+%)
*/ 7Gb(&'n
package NetFox; .f'iod-
[.e Y xZ{=
k^A Yg!~
public class Utility { cE x$cZRMI
!ra CpL9;
mPHn &4
public Utility() %y zFWDg
{ G-FTyIP>'
~;/\l=Xl
I+ipTeB^
} QiU!;!s
"Fv6u]Rv
//线程睡眠 X8T7(w<0%f
public static void sleep(int nSecond) \Yv<TzJ9
{ W68d"J%>_
try{ A:"J&TbBx
Thread.sleep(nSecond); G>hmVd
} %]9 <a
catch(Exception e) MxiU-
{ ailje
e.printStackTrace (); Is6<3eQ\x
} 1\d$2N"
} \FOX#|i)
W'{q
//日志 g%w@v$
public static void log(String sMsg) cK.T=7T
{ md[FtcY\
System.err.println(sMsg); CL(,Q8yG
} ^&t(O1.-
Qi^MfHW
Vy = fm
public static void log(int sMsg) ]y6`9p
{ [woR9azC
System.err.println(sMsg); 0y4z`rzTn
} }z&P^p)R
} Y[8w0ve-g
J.x>*3<l
OwGl&
/* t/cjz/]
**TestMethod.java (sw1HR
*/ \\jB@O
package NetFox; %l@Q&)f8e
sY,!Ir`/`
;_0)f
public class TestMethod { d#T8|#O"
7p}G!]`
qQR>z
public TestMethod() ;% *e}w0
{ ///xx/weblogic60b2_win.exe 8|[\Tp:;
try{ 78tWzO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); amf=uysr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /2oTqEqaV
SiteFileFetch fileFetch = new SiteFileFetch(bean); vCwDE~
fileFetch.start(); ?,r bD1
} "fLGXbNQ
catch(Exception e){e.printStackTrace ();} [d!C6FT
S=lA^#'UdX
. iq.H
} [Dq7mqr$
U'LO;s04m
$P]%Px!x
public static void main(String[] args) K@VXFV
{ -5\aL"?4
new TestMethod(); xiU-}H'o
} a<Pi J?
} 9#%(%s2+
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