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)); y<G@7?
} EcA@bZ0
for(int i=0;i<nEndPos.length-1;i++) ?w}E/(r
{ QPi]5z?
nEndPos = nStartPos[i+1]; :(,Eq?
} axl!zu*
nEndPos[nEndPos.length-1] = nFileLength; CL^MIcq?
} FuZ7xM,
} 4s!rrDN
~$0Qvyb>
0YsC@r47wL
//启动子线程 E47U &xL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q1G?e,Q
for(int i=0;i<nStartPos.length;i++) QOECpk-
{ 3q=A35*LT>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `};8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5N:THvh6o
nStartPos,nEndPos,i); L`yyn/2>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y7I')}SC
fileSplitterFetch.start(); G_wzUk=L
} V}#2pP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mW_<c,3D.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /"t*gN=wrF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x,\PV>
nEndPos = " + nFileLength); a*}ZT,V
// fileSplitterFetch[nPos.length-1].start(); GdqT4a\S
oEHUb?(p
-ISI!EU$
//等待子线程结束 bF88F_
//int count = 0; silTL_$
//是否结束while循环 xGQ958@
boolean breakWhile = false; eCYgi7?
^X%{]b K
9w -t9X>X
while(!bStop) :@TfhQV_=Q
{ t@Qs&DZ7k
write_nPos(); G[YbgG=9Y
Utility.sleep(500); &)Fp
breakWhile = true; ,zy4+GW
xzFV]
Go}C{(4T
for(int i=0;i<nStartPos.length;i++) %Dg]n4f
{ #Nt?4T<
if(!fileSplitterFetch.bDownOver) C:n55BE9
{ vjI>TIy
breakWhile = false; Vwp fkD`
break; [@OXvdTV
} R qS2Qo]
} %@Nuzdp
if(breakWhile) taXS>*|B
break; cvpcadN[
E3#}:6m
a;eV&~
//count++; Kc=&jCn
//if(count>4) ~y+QL{P4~
// siteStop(); L Ty[)
} Be{7Rj v
OLc/Vij;
@|xcrEnP}B
System.err.println("文件下载结束！"); qlJP2Ig~
} 3F ;+D
catch(Exception e){e.printStackTrace ();} (5%OAjW
} r%hnl9
}d2]QD#O
?d1H]f<M
//获得文件长度 T?W`g>yM
public long getFileSize() 3tMFJ ;*`
{ iWu$$IV?-
int nFileLength = -1; |1G/J[E
try{ o$>A;<
URL url = new URL(siteInfoBean.getSSiteURL()); " 1YARGu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~S)o('
httpConnection.setRequestProperty("User-Agent","NetFox"); B*A{@)_
0+b1R}!2
y; Up@.IG
int responseCode=httpConnection.getResponseCode(); QDS=M]
if(responseCode>=400) *5iNw_&
{ B98&JoS
processErrorCode(responseCode); g]9!Pi8jn
return -2; //-2 represent access is error dm1WC:b
} _eAZ_@
N5 SK_+
AD4KoT&
String sHeader; <">tB"="b
k9`Bi`wp
q&0Jl
for(int i=1;;i++) -A>1L@N
{ [ZS}P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Hq h
//Utility.log(in.readLine()); *p{wC r
sHeader=httpConnection.getHeaderFieldKey(i); GMLq3_'
if(sHeader!=null) -E#!`~&V
{ O0#wM-M
if(sHeader.equals("Content-Length")) ["}0umt
{ R=~+-^O!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3k;*xjv6@
break; m]JZ@
} t%<nS=u
} 6;U]l.
else 4f<%<Z
break; \3(d$_:b
} +]/_gz
} 5An|#^]
catch(IOException e){e.printStackTrace ();} EUj'%;sz-
catch(Exception e){e.printStackTrace ();} ~HD:Y7
CRvUD.D
Sc;WraEn2
Utility.log(nFileLength); GcQO&oq|
w+bQpIPM
8 M3Q8&
return nFileLength; 3Xaw
} _B)LRD+Hj
bS_!KU
d ! A)H<Zt
//保存下载信息（文件指针位置） [>+(zlK"
private void write_nPos() G<,@|6"w
{ f_X]2in
try{ '/kSUvd
output = new DataOutputStream(new FileOutputStream(tmpFile)); FMB\$(g
output.writeInt(nStartPos.length); oop''6`C%
for(int i=0;i<nStartPos.length;i++) IC>OxYg*
{ 306C_M\$
// output.writeLong(nPos); CXGq>cQ=d
output.writeLong(fileSplitterFetch.nStartPos); ?y!0QAIXK
output.writeLong(fileSplitterFetch.nEndPos); Q@hx+aM
} ^HumyDD6
output.close(); P&C,EE$
} Y[9x\6 _E
catch(IOException e){e.printStackTrace ();} 7Xm7{`jH
catch(Exception e){e.printStackTrace ();} .asHFT7]9
} a0OH
Asicf{HaX
ipnvw4+
//读取保存的下载信息（文件指针位置） .?9+1.`
private void read_nPos() ?c0OrvM
{ @yPa9Ug(V
try{ K~OfC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g4_DEBh
int nCount = input.readInt(); ,#rl"
nStartPos = new long[nCount]; 703=.xj
nEndPos = new long[nCount]; |U%S<X
for(int i=0;i<nStartPos.length;i++) O/$pT%D1x
{ f m.-*`ax
nStartPos = input.readLong(); oX@nWQBc_
nEndPos = input.readLong(); utKtxLX"
} 'x BBQP
input.close(); B\A2Vm`&
} kPF[E5
catch(IOException e){e.printStackTrace ();} :<4:h.gO8
catch(Exception e){e.printStackTrace ();} FW(y#Fmqs
} :Eq=wbAw
T1c2J,+}R
mw";l$Aq}
private void processErrorCode(int nErrorCode) [_Y\TdR
{ nJ |O,*`O
System.err.println("Error Code : " + nErrorCode); T;X8T
} X6%w6%su5
[TvH7ott'1
X*VHi
//停止文件下载 Xjc{={@p3
public void siteStop() \ Xow#@[
{ Q3,`'[ F
bStop = true; _@jBz"aq\
for(int i=0;i<nStartPos.length;i++) _In[Z?P}
fileSplitterFetch.splitterStop(); 6?Ul)'
C#[YDcp4
Px5ArSS
} My0h9'K
} ~` v7
//负责部分文件的抓取 @kC>+4s!
**FileSplitterFetch.java l j*ELy
*/ <n< @ O5
package NetFox; fRC(Yyx
H[?~u+
ja*k\w{U'
import java.io.*; _;",7bT80
import java.net.*; `W< 7.
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+,<\LIP
public class FileSplitterFetch extends Thread { w~@.&
U.~,Bwb
o-2FGM`*VB
String sURL; //File URL 4 F~e3
long nStartPos; //File Snippet Start Position Oi+(`
long nEndPos; //File Snippet End Position \dSMF,E
int nThreadID; //Thread's ID :D6"h[7
boolean bDownOver = false; //Downing is over `X]TIMc:Ad
boolean bStop = false; //Stop identical aG;6^$H~
FileAccessI fileAccessI = null; //File Access interface |xyr6gY
K[Bq,nPo
pZp|F
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X~t]qT
{ XH&Fn+
this.sURL = sURL; 3>qUYxG8
this.nStartPos = nStart; VQF!|*#
this.nEndPos = nEnd; B4 5B`Ay
nThreadID = id; Vc|r(lM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \)859x&(
} n-[J+DdB
mcAg,~"HB
w V&{w7
public void run() =SPuOy8
{ w_|R.T\7
while(nStartPos < nEndPos && !bStop) 2P`QS@v0a=
{ CLU!/J$!
'jWd7w~(
c0jdZ#H
try{ &WAO.*:y
URL url = new URL(sURL); n~N>c*p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :" Q!Q@>
httpConnection.setRequestProperty("User-Agent","NetFox"); j|gv0SI_ w
String sProperty = "bytes="+nStartPos+"-"; TtEc~m
httpConnection.setRequestProperty("RANGE",sProperty); D(xgadr
Utility.log(sProperty); , "w`,c>!
Vzf{gr?
O~F/{:U
InputStream input = httpConnection.getInputStream(); R>H*MvN
//logResponseHead(httpConnection); '0x`Oh&PK
&P{
z!27#gbL
byte[] b = new byte[1024]; Gs%IZo_
int nRead; 1><\3+8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j(/Bf m
{ xMJF1O?3
nStartPos += fileAccessI.write(b,0,nRead); vf(8*}'!Q
//if(nThreadID == 1) ;Vc@]6Ck
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6J0HaL
} Icf 4OAx
#+Z3!VS
2xRb$QF
Utility.log("Thread " + nThreadID + " is over!"); uV.3g 1m
bDownOver = true; QA7SQcd,
//nPos = fileAccessI.write (b,0,nRead); eA9U|&o
} _KiaeVE
catch(Exception e){e.printStackTrace ();} P lJl#-BO
} fo~8W`H&
} Q#xeu
'SF+P)Kmz
|eL&hwqzG
//打印回应的头信息 wJ-G7V,)
public void logResponseHead(HttpURLConnection con) 9],;i7c
{ k^AI7H
for(int i=1;;i++) iK{q_f\"
{ 2f\;#-
String header=con.getHeaderFieldKey(i); :/fG %e
if(header!=null) x][vd^iW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1BQTvUAA
Utility.log(header+" : "+con.getHeaderField(header)); |gEA.} pY
else R_J=x
break; 3U=q3{%1
} [Z6]$$!#2
} 6dTq&GZ\
dq~p]h~,H
AH`D&V
public void splitterStop() D3Lu]=G
{ F^bC!;~x
bStop = true; p#~'xq
} *0M#{HQ
B[7|]"L@
<\Nf6>_qEM
} @<Au|l`
)l*H$8
SzkF-yRd
/* s`Fv!
**FileAccess.java lM Gz"cym
*//文件访问(定位，写) J411bIxD+q
package NetFox; hk4f)z
import java.io.*; ?cdSZ'49[
ep<Ad
{LTb-CB
public class FileAccessI implements Serializable{ Qfo'w%px
H4 Y7p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :Bp{yUgi@
RandomAccessFile oSavedFile; M`\c'|i/
long nPos; d$)'?Sf]h
[^ck;4q
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public FileAccessI() throws IOException p%Ae"#_X%
{ ZV}BDwOFI
this("",0); {OP-9P=p
} ~jAOGo/&6
=BY)>0?z
B5Rmz&
public FileAccessI(String sName,long nPos) throws IOException )xCpQ=nS
{ ]3hz{zqV^
oSavedFile = new RandomAccessFile(sName,"rw"); I=&5mg=m
this.nPos = nPos; _v4TyJ
oSavedFile.seek(nPos); _=B(jJZ
} ?@Z~i]gE[V
mH*42XC*
evsH>hE^
public synchronized int write(byte[] b,int nStart,int nLen) C-]H+p
{ q]:+0~cz
int n = -1; n"Ec%n
try{ l)D18
oSavedFile.write(b,nStart,nLen); Y{Kpopst
n = nLen; <'op
} ;&e5.K+.Z
catch(IOException e) VuFMjY
{ LfyycC2E
e.printStackTrace (); !;lA+O-t
} >4GhI65
7>xxur&
N'Va&"&73>
return n; _6THyj$f
} K2nq2Gbn
1iaNb[:QX
N J:]jd
} k#`.!yI,
O]w&uim
W5}.WFu
/* CU6rw+Vax
**SiteInfoBean.java 2N)=fBF%-
*/ qfE/,L(B
package NetFox; %^^2
:BCjt@K}
ttLChL
public class SiteInfoBean { -Qo`UL.}
dW;{,Q
)vOZp&
private String sSiteURL; //Site's URL ?yddr`?W
private String sFilePath; //Saved File's Path )z3mS2
private String sFileName; //Saved File's Name oe`oUnN
private int nSplitter; //Count of Splited Downloading File T2Cdw\
S+|aCRS
!6|Kpy8
public SiteInfoBean() >!A&@1[M
{//nSplitter的缺省值为5 !l~tBJr*sB
//default value of nSplitter is 5 4PTHUyX
this("","","",5); ItQIM#
} e`4OlM]
kJy<vb~
/YHBhoat
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :<gmgI
{ .Xo, BEjE/
sSiteURL= sURL; 1W8[ RET
sFilePath = sPath; ^Ot+,l)
sFileName = sName; 7u,56V?X
this.nSplitter = nSpiltter; 3nd02:GF
{#uX
8~:qn@Z|E
} f'Wc_L)
sBS\S
T_6,o[b8
public String getSSiteURL() $rs7D}VNc
{ T{]Tb=
return sSiteURL; p}uL%:Vr
} t?28s/?
9/D+6hJ]:
go6Hb>
public void setSSiteURL(String value) y&lj+j
{ P\iw[m7O
sSiteURL = value; /+2^xEIjE
} @`k!7? Sq
=Z2U
en!cu_]t
public String getSFilePath() ,bmiIW%
{ #g4X`AHB
return sFilePath; xex/L%!Rj
} 8_U*_I7(
dSsMa3X[n
zi2hi9A
public void setSFilePath(String value) #$K\:V+ 4
{ P`[6IS#\S
sFilePath = value; #1z}~1-
} S#!PDg
j!&g:{ e
+;`Cm.Iu
public String getSFileName() /QHvwaW[
{ o&rejj#
return sFileName; }pPxN@X
} Kx*;!3-V$
PPDm*,T.
.pu]21m=
public void setSFileName(String value) `iv,aQ '
{ GUmOK=D >
sFileName = value; M^mS#<!y
} oQ8W0`bZa
@`$8rck`
Eo)Q> AM
public int getNSplitter() ~8`r.1aUO
{ e_g7E+6
return nSplitter; *M/3 1qI
} FlD !?
& @^|=>L
DDN#w<#
public void setNSplitter(int nCount) 5Tb93Q@c
{ }OI;M^5L
nSplitter = nCount; Jnb>u*7,
} VZb0x)w
} &Dqg<U
H~J#!3
AmRppbj/wO
/* Th`IpxV
**Utility.java oVb6,Pn
*/ ]^VC@$\)+
package NetFox; zvdtP'&uj
~(-B%Az
rh${pHl
public class Utility { vov"60K
$eX; 2
4tCyd5u a8
public Utility() 7>wSbAR<
{ 6Ei>VcN4a
$?(fiFC
IBQmm(+v
} Ts|&_|
B:&/*HU
//线程睡眠 H;G*tje/M
public static void sleep(int nSecond) K)sO
{ (3%NudkwT
try{ \.9-:\'(
Thread.sleep(nSecond); %z`bu2
} <{3VK
catch(Exception e) :I+%v
{ lk%rE
e.printStackTrace (); .^l;3*X@
} -_%n\#
} kJlRdt2
K {!eHTU
//日志 ?X]7jH<iw;
public static void log(String sMsg) EbY%:jR
{ [|<|a3']|
System.err.println(sMsg); "DjD"?/b
} }PK8[N
i0L)hkV
;I:jd")
public static void log(int sMsg) ljlQ9wb[s
{ V!DQ_T+a
System.err.println(sMsg); ds4ERe /
} iU~oPp[e
} Zc{at}{
O6YYOmt3
.?<,J
/* -wW%+wH
**TestMethod.java U5Q `r7
*/ 7$\;G82_
package NetFox; yw{GO([ZQ
hJkIFyQ{j
IyL2{5
public class TestMethod { ^bexXYh
rKg5?.
<Ktx*(D
public TestMethod() R3jhq3F\Y
{ ///xx/weblogic60b2_win.exe wx>BNlT@?
try{ 5WP)na6"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \6T&gX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H8mmmt6g
SiteFileFetch fileFetch = new SiteFileFetch(bean); J3oH^
fileFetch.start(); u0A.I_
} TC<_I0jCh
catch(Exception e){e.printStackTrace ();} y7u"a)T
=BMON{K
]pzf{8%
} f]qPxRw
{3i.U028]
0AZ Vc
public static void main(String[] args) ido'<;4>
{ ?N~rms e
new TestMethod(); ~Ub'5M
} jRmv~]
} !eMz;GZ
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