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)); n,sY\=vB
} . ,R4WA,
for(int i=0;i<nEndPos.length-1;i++) wVE:X3Ei
{ :u-.T.zZl
nEndPos = nStartPos[i+1]; OXCQfT@\
} cix36MR_
nEndPos[nEndPos.length-1] = nFileLength; +Vy_9I(4Z
} d;44;*D
} ?:/|d\,7@
Egf^H>,.M
="3,}qR
//启动子线程 )x[HuIRaa
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Hk9U&j$
for(int i=0;i<nStartPos.length;i++) >0T Za
{ Q;wB{vr$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5r7h=[N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c&m9)r~zP
nStartPos,nEndPos,i); gc,Ps
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;RHNRVP
fileSplitterFetch.start(); c3W BALdh
} gl "_:atW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jI0]LD1k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J*K<FFp3<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n|C|&
nEndPos = " + nFileLength); agT7=hX].
// fileSplitterFetch[nPos.length-1].start(); 2*Q3.2 Z
TGpSulg7
Y`^o7'Z2^P
//等待子线程结束 /[?Jylj
//int count = 0; t7^D-l
//是否结束while循环 P7r4ePtLk{
boolean breakWhile = false; p:tN642
Noz&noq
enumK\
while(!bStop) oIxH3T
{ {:)vwUe{
write_nPos(); )E-E0Hl>7
Utility.sleep(500); .eY`Ri<3t
breakWhile = true; De]^&qw(
n1 v,#GE
W>$BF[x!{
for(int i=0;i<nStartPos.length;i++) }# Xi`<{
{ I.a0[E/,
if(!fileSplitterFetch.bDownOver) [gZDQcU
{ u`6/I#q`
breakWhile = false; VDa|U9N
break; a(|xw
} +?V0:Kz]
} !tBeuemN%
if(breakWhile) U`1l8'W}:#
break; 0'@u!m?
N&x:K+Zm.
=G>.-Qfs
//count++; PG"@A
//if(count>4) QnU0"_-
// siteStop(); kwF]TO S
} _:%U_U
/RqhykgZ
?l9=$'
System.err.println("文件下载结束！"); 4=s9A
} 9[sG1eP!
catch(Exception e){e.printStackTrace ();} $3 vhddO
} =qX*]
:l`i4kx
!7c'<[+Hm
//获得文件长度 [TEcg^
public long getFileSize() LU(%K{9
{ 8f-:d]
int nFileLength = -1; h?A'H RyL~
try{ \k4pK &b
URL url = new URL(siteInfoBean.getSSiteURL()); :d({dF_k;p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )-q\aX$])
httpConnection.setRequestProperty("User-Agent","NetFox"); C fSl 54
eJ:Yj ~X`<
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int responseCode=httpConnection.getResponseCode(); A;T[['
if(responseCode>=400) P}l#VJWp
{ iD`k"\>9
processErrorCode(responseCode); ^9'$Oa,*
return -2; //-2 represent access is error 3SFg#
} >fbo r'|
gLx/w\l6
yLB~P7K
String sHeader; YLmjEs%
RpAiU
%yvA
for(int i=1;;i++) HT&p{7kFm
{ _4!{IdR
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e{JVXc[D
//Utility.log(in.readLine()); 1vsu[n
sHeader=httpConnection.getHeaderFieldKey(i); fCr\u6Tb
if(sHeader!=null) ZYDWv/u
{ &N9IcNP
if(sHeader.equals("Content-Length")) D2)i3vFB
{ /yp/9r@T0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v~aLTI
break; -nGwuEngP
} |=u96G~N
} W]@6=OpH
else IhwN],-V
break; Ysl9f1>%
} ke^d8Z.
} hMWo\qM
catch(IOException e){e.printStackTrace ();} yYk|YX(7U
catch(Exception e){e.printStackTrace ();} w#<p^CS
jOv~!7T
{!y<<u1
Utility.log(nFileLength); LGfmUb-{]
N;g$)zCV1
NFV_+{X\
return nFileLength; CdNih8uG
} *k4+ioFnKE
ZBC@xM&-
<uC<GDO
//保存下载信息（文件指针位置） ? osfL
private void write_nPos() h&P {p _Y
{ {Y^c*Iqn
try{ z 7@ 'CJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); x*J|i4
output.writeInt(nStartPos.length); 4M7^ [G
for(int i=0;i<nStartPos.length;i++) ^9s"FdB]24
{ 4/f[`].#W
// output.writeLong(nPos); W%WC(/hor
output.writeLong(fileSplitterFetch.nStartPos); 7g8B'ex J
output.writeLong(fileSplitterFetch.nEndPos); %pqL-G
} UC(9Dz
output.close(); 5c)<'EP
} )6g&v'dq
catch(IOException e){e.printStackTrace ();} BPqwDjW
catch(Exception e){e.printStackTrace ();} 1MpX] j8C#
} C-&#r."L
,;c{9H
-C=]n<ak
//读取保存的下载信息（文件指针位置） [C2kK *JZ
private void read_nPos() \DaLHC~
{ N:d D*[QZ
try{ hg{ &Y(J!U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?f9$OLEB
int nCount = input.readInt(); (%.</|u
nStartPos = new long[nCount]; VSx%8IM+X
nEndPos = new long[nCount]; bIq-1 Y(
for(int i=0;i<nStartPos.length;i++) 1BTgGF
{ |KTpK(6p
nStartPos = input.readLong(); (5>{?dR)|
nEndPos = input.readLong(); y. Tct.
} A xRl*B
input.close(); -}NAb^d
} ^971<B(v
catch(IOException e){e.printStackTrace ();} juR
catch(Exception e){e.printStackTrace ();} 1 iquHn
} p FXd4*
y{:]sHyG
py}.00it
private void processErrorCode(int nErrorCode) t;oT {Hge
{ 1`nc8qC
System.err.println("Error Code : " + nErrorCode); xu`d`!Tx
} %+D-y+hn
*1R##9\jU7
q#.rYzl0
//停止文件下载 VyRW'
public void siteStop() kbD*=d}3{
{ sb8z_3
bStop = true; ?&{S~[;l
for(int i=0;i<nStartPos.length;i++) fMgcK$
fileSplitterFetch.splitterStop(); Xqc'R5Cw
>N :|Km\
$:xF)E
} xU#]w6
} Q9Q!9B@
//负责部分文件的抓取 'O!Z:-qE
**FileSplitterFetch.java V< 2IIH5^
*/ Y'3kE
package NetFox; ?3.(Vqwog
Z $ p^v*y
GZxglU,3T
import java.io.*; ?v0A/68s#
import java.net.*; %V@Rk.<
Q=)"om
a15,'v$O
public class FileSplitterFetch extends Thread { #L|JkBia
5q0BG!A%T
~gSF@tz@
String sURL; //File URL S7@ZtFf
long nStartPos; //File Snippet Start Position U[K0{PbY
long nEndPos; //File Snippet End Position @n5;|`)\
int nThreadID; //Thread's ID p~v2XdR
boolean bDownOver = false; //Downing is over Rfkzv=<"X
boolean bStop = false; //Stop identical kKFuTem_3
FileAccessI fileAccessI = null; //File Access interface (cPeee%Q
5n&)q=jk=
0KWy?6 X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Eg287B
{ 1t~S3Q||>]
this.sURL = sURL; R#[QoyJ
this.nStartPos = nStart; GU;TK'Yy?
this.nEndPos = nEnd; n1k$)S$iiy
nThreadID = id; Vz=j)[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f4 Sw,A
} m!FM+kge
c0,gfY%sI$
<;TP@-a
public void run() $=@9 D,R
{ '&_y*"/c
while(nStartPos < nEndPos && !bStop) Vsm%h^]d
{ h&:Q$*A>
'Wx\"]:
'.}6]l
try{ V29S*
URL url = new URL(sURL); K~fDv i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SSA%1l2!
httpConnection.setRequestProperty("User-Agent","NetFox"); b_K?ocq
String sProperty = "bytes="+nStartPos+"-"; I;kUG_c(4
httpConnection.setRequestProperty("RANGE",sProperty); g-{<v4NGI
Utility.log(sProperty); rSc,\upz
x]mye
*x#&[>
InputStream input = httpConnection.getInputStream(); w#gU1yu
//logResponseHead(httpConnection); FS]+s>
l/y Kc8^<
t?#vb}_
byte[] b = new byte[1024]; 21)-:rS
int nRead; hq&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]y)R C-N
{ Ilt L@]e
nStartPos += fileAccessI.write(b,0,nRead); QB.*R?A
//if(nThreadID == 1) X'3`Q S:!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zDGg\cPj9
} U d=gdsL
&d|VH y+
`)( <g
Utility.log("Thread " + nThreadID + " is over!"); ]%Q]C 8[C
bDownOver = true; [/fwt!
//nPos = fileAccessI.write (b,0,nRead); ;&t1FH#=
} }TAGr 0
catch(Exception e){e.printStackTrace ();} +y{93nl
} bTy'5"
} .xc/2:m9
]`i@~Z h\
r* /XB0
//打印回应的头信息 Gad2EEZ%0
public void logResponseHead(HttpURLConnection con) %\zCOfN
{ :x*|lz[
for(int i=1;;i++) &L~31Ayj&
{ wor'=byh\
String header=con.getHeaderFieldKey(i); |@Idf`N$
if(header!=null) J^+$L"K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /x8C70W^
Utility.log(header+" : "+con.getHeaderField(header)); b]qfcV
else Mbi+Vv-
break; Mpl,}Q!c
} &t%&l0
} p7=^m>Z6
d`q)^
jv#" vQ9A]
public void splitterStop() 'N5r2JL[w
{ l<MCmKuYp
bStop = true; "a`0w9Mm}
} 6x3Ew2
vJjj+:
Vx4pP$S
} <~8f0+"
.=w`T #L
zvs 2j"lb
/* K|J#/
**FileAccess.java <x;[ H%
*//文件访问(定位，写) c$SxDYG
package NetFox; zB7dCw
import java.io.*; WxP4{T* <
"BNmpP
Ywb)h^{!
public class FileAccessI implements Serializable{ ;\&bvGj8V
l0bT_?LhK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5xV/&N
RandomAccessFile oSavedFile; Mn{Rg>X
long nPos; 1Y0oo jD
-a^sX%|Bl
4a-F4j'
public FileAccessI() throws IOException ?[fl$EG
{ 7Sv5fLu2
this("",0); rW>'2m6HU
} .BTT*vL-
a}]@o"
9-<V%eNX
public FileAccessI(String sName,long nPos) throws IOException +fR`@HI
{ =]k_Oq-1h
oSavedFile = new RandomAccessFile(sName,"rw"); "@|V.d@
this.nPos = nPos; {7szo`U2
oSavedFile.seek(nPos); \z?;6A
} g wiC ,
.Zz7LG{
Iur} ZAz
public synchronized int write(byte[] b,int nStart,int nLen) _4#psxl[M
{ 83(P_Y:
int n = -1; 0#nXxkw
try{ O g~"+IGp
oSavedFile.write(b,nStart,nLen); t/BiZo|zl
n = nLen; Gjh7cm>
} <NsT[r~C
catch(IOException e) ]b$,.t5
{ bL[W.O0
e.printStackTrace (); 'V{k$}P2
} 4T^WRS
7ZnQ] ?
tzN;;h4C
return n; X~4:sJ\P=
} iR=aYT~
6%y: hLT
^%@.Vvz<
} e-meUf9
Q1B!W
&y?B&4|hM
/* ~q>ilnL"h
**SiteInfoBean.java e28#Yh@U
*/ }7v2GfEkM
package NetFox; eci\Q,
AVZ@?aJgF
9R3=h5Y
public class SiteInfoBean { +rX,Sl`/
zvj >KF|y
@/iLC6QF
private String sSiteURL; //Site's URL '>$A7
private String sFilePath; //Saved File's Path gf>5xf{M
private String sFileName; //Saved File's Name p}z0(lQ*~
private int nSplitter; //Count of Splited Downloading File Pl6=._
!7DS
bhYaG i0
public SiteInfoBean() ?A>-_B
{//nSplitter的缺省值为5 u] b6>
//default value of nSplitter is 5 3!x)LUWfWY
this("","","",5); "de:plMofy
} ?H?r!MZ%
eu;^h3u;b
`#bcoK5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ma~`&\xE
{ W&#Nk5d
sSiteURL= sURL; w6 .HvH-@?
sFilePath = sPath; 7h~M&\M
sFileName = sName; yhmW-#+^e
this.nSplitter = nSpiltter; &jcr7{cD
\266N;JrN
{n'}S(
} Rz]bCiD3 B
E{J;-+t
{HeMdGn9
public String getSSiteURL() ?K"]XXsI
{ E*vi@aI
return sSiteURL; G y2XjO8b
} 5KzU&!Zh9
8iRQPV-"_
V ALYA=w/
public void setSSiteURL(String value) 2~ a4ib
{ " B1' K8
sSiteURL = value; aHw VoT
} s~CA @
kQ+5pFo3
_U %B1s3y
public String getSFilePath() L<n_}ucA
{ s0CRrMk
return sFilePath; k?,g:[4!
} IkkrnG8
_4+1c5Q!
7VraWW`H'
public void setSFilePath(String value) #@G2n@Hj
{ O?_'6T
sFilePath = value; (,>`\\
} |d$aISO`
xUYSD
& CgLF]
public String getSFileName() RN0Rk 8AC
{ S1."2AxO
return sFileName; 4'M#m|V
} eF9LZ"-s
=g ]C9'I3
v|e>zm<
public void setSFileName(String value) U w)1yzX
{ R)v`ZF,/b
sFileName = value; |kn}iA@72p
} kDrGl{U}
'EQAG' YV
Aq-v3$XL
public int getNSplitter() ;Zw28!#Rt
{ Tb[GZ,/%;
return nSplitter; /cg!Ap5
} ;-3M
2:]Sy4K{
|laqy`D
public void setNSplitter(int nCount) I^o^@C
{ <rkF2-K,
nSplitter = nCount; >U17BGJ.
} (HEjmQjE
} >[#4Pb7_Y
?FLjvmE9
?h5Y^}8Qg
/* 8n56rOW!
**Utility.java m+L:\mvA
*/ ;,<s'5icyg
package NetFox; B::vOg77
TZ/u"' ZS
"/q6E
public class Utility { wL{Qni3A
4B|f}7%\
)_BteLo-
public Utility() ?VJ Fp^Ra
{ )TLDNpH?J
uJ%ql5XDV
=Ij;I~
} :%0Z
U_:/>8})d
//线程睡眠 R\XJ
public static void sleep(int nSecond) %c&h:7);
{ 3KqylC&.
try{ iaMZ37
Thread.sleep(nSecond); g3y44GCV
} KMZ% 1=a
catch(Exception e) S_)va#b#
{ Dx8^V%b
e.printStackTrace (); y(%6?a @
} )t|M)zJ
} ].$N@tC
MQI6e".
//日志 //`X+[bMG
public static void log(String sMsg) ~ >6(@~6
{ (LnKaf8
System.err.println(sMsg); \X(.%5xC
} $(GXlhA
1(-)$m8}
ZqSczS7uf
public static void log(int sMsg) 8garRB{
{ ~;MRQE
System.err.println(sMsg); lwV#j}G
} 5-MI7I@l
} c+q4sNnE
OH&&d=~
VlKWWQj
/* O)&V}hU*
**TestMethod.java Z/%>/
*/ m~2PpO
package NetFox; T8v>J4@t
1>n@`M8}
IF<jq\M
public class TestMethod { -?j'<g0
tFG&~tNc
huO_ARwK'
public TestMethod() -(Yq$5Zc&
{ ///xx/weblogic60b2_win.exe aC;OFINK
try{ y3d`$'7H>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C}7Sh6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JVN0];IL}
SiteFileFetch fileFetch = new SiteFileFetch(bean); xgfK0-T|[
fileFetch.start(); Z/O5Dear/h
} 9OX&;O+5
catch(Exception e){e.printStackTrace ();} T$SGf.-
}LOAT$]XI
?v6xaVg:
} {>90d(j
[/'W#x
oB+drDp8U
public static void main(String[] args) x2l~aw#?
{ e~xN[Q\0]
new TestMethod(); |'.\}xt7
} BjSLbw-C
} )[>{ Ie2
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