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)); "&C'K
} 4H1s"mP<
for(int i=0;i<nEndPos.length-1;i++) b(~NqV!i
{ 6Ajiz_~U
nEndPos = nStartPos[i+1]; OkFq>;{a
} pV>/"K
nEndPos[nEndPos.length-1] = nFileLength; bLNQ%=FjO
} < ^J!*>
} q)!{oi{x(
Iqo4INGIi
<ygkK5#q
//启动子线程 k ( R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -M[5K/[
for(int i=0;i<nStartPos.length;i++) k`TEA?RfQ
{ eKLxNw5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PU-;Q@< E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -JUv'fk
nStartPos,nEndPos,i); 0]NsT0M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UGR5ILf
fileSplitterFetch.start(); b/S4b
} ]p#Zdm1EL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KN+*_L-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A?6b)B/e?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eUBk^C]\
nEndPos = " + nFileLength); R8HA X
// fileSplitterFetch[nPos.length-1].start(); *(r85lEou)
p]pFZ";70
m0\(a_0V
//等待子线程结束 qe\j$Cjy
//int count = 0; !})+WSs'"s
//是否结束while循环 ]HCt%5
boolean breakWhile = false; }b,a*4pN
>xH3*0Lp
!^\|r<2M
while(!bStop) 0>.'w\,87B
{ )EcF[aO
write_nPos(); $'[( DwLS
Utility.sleep(500); ][_:{ N/
breakWhile = true; 9$d (`-&9p
L!e@T'
78NAcP~6c
for(int i=0;i<nStartPos.length;i++) "w_(p|cm=
{ TJO|{Lxm
if(!fileSplitterFetch.bDownOver) Gzm[4|nO^
{ v_G4:tY
breakWhile = false; gw5CU)r4$
break; I#9K/[
} =#>P!
} qLPI^g,
if(breakWhile) } 10Dvt>+
break; wePMBL1P*
w|$;$a7)
+ ^~n09
//count++; iAXx`>}m
//if(count>4) DpTQPu9
// siteStop(); @zPWu}&m
} n287@Y4Ru
&f!!UZMt)
~[,E i k
System.err.println("文件下载结束！"); Ie+z"&0
} {~d4;ht1Y
catch(Exception e){e.printStackTrace ();} bg 7b!t1F
} g[Yok`e[
zM)o^Fn2
vguqk!eo4
//获得文件长度 |r3eq4$Am
public long getFileSize() ,@>B#%Nz
{ !X#=Pt[,
int nFileLength = -1; U>:p`@
try{ A}oR,$D-
URL url = new URL(siteInfoBean.getSSiteURL()); cvc.-7IO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'MC)%N,
httpConnection.setRequestProperty("User-Agent","NetFox"); j[=f;&1
q 2=^l
oR3$A :!P=
int responseCode=httpConnection.getResponseCode(); ]aaHb
if(responseCode>=400) Lqz}h-Ei
{ >Axe7<l
processErrorCode(responseCode); i>0bI^H
return -2; //-2 represent access is error XSZW9/I-(|
} vbA9V<c&
Be}Cj(C
HK ;C*;vC%
String sHeader; f)gA.Rz
sy]1Ba%
KXR
for(int i=1;;i++) hS<x+|'l
{ 9-L.?LG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h{>8W0W*
//Utility.log(in.readLine()); !m^WtF
sHeader=httpConnection.getHeaderFieldKey(i); 6Lz&"C,`
if(sHeader!=null) Le_?x
{ Bv/v4(G5g
if(sHeader.equals("Content-Length")) znu?x|mV
{ mEE/Olh W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y+X%qTB
break; AMtFOXx%I
} 33 N5>}
} {L.0jAwB
else HW{+THNj
break; BeP0lZ
} !f"@pR6
} o<%Sr*
catch(IOException e){e.printStackTrace ();} R#Ss_y
catch(Exception e){e.printStackTrace ();} F5EKWP
9#pl BtQ**
6IeHZ)jGj
Utility.log(nFileLength); ~Uga=&
vbh\uv&
/A{znE
return nFileLength; !o>/gI`
} u QCQ$
;:'A{&0N
PBkKn3P3
//保存下载信息（文件指针位置） 'p{>zQ\5
private void write_nPos() Jd)|==yD
{ Z=wLNmH
try{ "rkP@ja9n
output = new DataOutputStream(new FileOutputStream(tmpFile)); [t?ftS
output.writeInt(nStartPos.length); !9V_U
for(int i=0;i<nStartPos.length;i++) uv._N6mj
{ /SP^fB*y
// output.writeLong(nPos); B;_M52-B
output.writeLong(fileSplitterFetch.nStartPos); .K:>`~<)
output.writeLong(fileSplitterFetch.nEndPos); G$`/86A)
} 4.R >mN[
output.close(); &~uzu{
} LVO`+:
catch(IOException e){e.printStackTrace ();} -w^E~J0*L
catch(Exception e){e.printStackTrace ();} wYNh0QlBH
} ].`i`.T
N"FQMxqm
&K|CH? D
//读取保存的下载信息（文件指针位置） Qs</.PO
private void read_nPos() opdi5e)jK
{ V"\t
try{ IDwneFO
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); QiB:K Pz[
int nCount = input.readInt(); Z\`uI+`
nStartPos = new long[nCount]; 6(X(f;MEl
nEndPos = new long[nCount]; %'@&j2j>
for(int i=0;i<nStartPos.length;i++) e|xRK?aVBu
{ r@k&1*&
nStartPos = input.readLong(); hb[K.`g
nEndPos = input.readLong(); !=eui$]
} ;-U:t4
input.close(); c1!h;(&
} F&I^bkvh
catch(IOException e){e.printStackTrace ();} # l}Y1^PDd
catch(Exception e){e.printStackTrace ();} Y+j|T`d
} Smg,1,=
q=g;TAXZl
/R@eOl}D
private void processErrorCode(int nErrorCode) &o:wSe
{ sIg{a(1/
System.err.println("Error Code : " + nErrorCode); q[7C,o>/
} JZ80|-c
*G2p;n=2
&5c)qap;n
//停止文件下载 WVp14Z?k
public void siteStop() qKZ~)B j
{ Bo)w#X
bStop = true; O`Nzn~),x
for(int i=0;i<nStartPos.length;i++) } n_9d.
fileSplitterFetch.splitterStop(); qp'HRh@P2:
EXoT$Wt{$
53@*GXzE
} |*jnJWH4:
} ~b\bpu
//负责部分文件的抓取 ,Q2`N{f
**FileSplitterFetch.java .kGg}
*/ <.+hV4,3
package NetFox; lc#su$xR>
pz#oRuujY
CGny#Vh
import java.io.*; 'I\bz;VT
import java.net.*; jQ(qaX&
2["bS++?
y kwS-e
public class FileSplitterFetch extends Thread { 1Ep!U#Del
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mGwBbY+5n
String sURL; //File URL 7WKb| /#;
long nStartPos; //File Snippet Start Position dI{)^
long nEndPos; //File Snippet End Position K'Bq@6@C g
int nThreadID; //Thread's ID h@@2vs2
boolean bDownOver = false; //Downing is over D3|y|Dr
boolean bStop = false; //Stop identical @e3O=_m-
FileAccessI fileAccessI = null; //File Access interface 8v5cQ5Lc
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[f&ja[m q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~UEft
{ ^4h/6^b0c
this.sURL = sURL; <jY"+@rF
this.nStartPos = nStart; 0a ZplE,
this.nEndPos = nEnd; ggXg4~WL
nThreadID = id; z3[ J>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |ILj}4ZA7
} \Om.pOz
yiWBIJ2Wu9
r`HtN{6r
public void run() ezgP\ct
{ {D 9m//x
while(nStartPos < nEndPos && !bStop) G;>b}\Ng
{ 9jCn|+
d[6[3B
w0q.cj@nd
try{ _>S."cm}!k
URL url = new URL(sURL); pmv;M`_|R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iQ~;to;Y
httpConnection.setRequestProperty("User-Agent","NetFox"); D/5 ah_;
String sProperty = "bytes="+nStartPos+"-"; sy0|=E*;8"
httpConnection.setRequestProperty("RANGE",sProperty); 3#!}W#xv
Utility.log(sProperty); Akb#1Ww4
#kR8v[Z
T;-&3
InputStream input = httpConnection.getInputStream(); eR$qw#%c*
//logResponseHead(httpConnection); 2I3MV:5
]O,;t>
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byte[] b = new byte[1024]; EuOrwmdj
int nRead; &-dyg+b3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DZ<q)EpC
{ & w&JE]$ 5
nStartPos += fileAccessI.write(b,0,nRead); lc?9B
//if(nThreadID == 1) ?suxoP%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /5b,&
} 5 <X.1T1
k2(B{x}L
;G|5kvE>
Utility.log("Thread " + nThreadID + " is over!"); ,qz$6oxh\
bDownOver = true; S%uwQ!=O8
//nPos = fileAccessI.write (b,0,nRead); *9Ej fs7L
} ]+@@{?0
catch(Exception e){e.printStackTrace ();} VJ8cls<
} lyc ]E 9
} [K1RP.
=]X_wA;%
]|KOc& y:I
//打印回应的头信息 zy^t95/m
public void logResponseHead(HttpURLConnection con) ecfw[4B`
{ G~b/!clN
for(int i=1;;i++) i|?EgGFG
{ ,UNCBnv1
String header=con.getHeaderFieldKey(i); FZf{kWH
if(header!=null) dT?/9JIv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); efW<
Utility.log(header+" : "+con.getHeaderField(header)); O10,h(O
else #fk#RNt
break; j?<>y/IR
} OE[|1?3
} 5 YjqN
%#kml{I
*DfwTbg|
public void splitterStop() E}LYO:
{ 4HG;v|Cp
bStop = true; XRARgWj
} -9W)|toWb"
O~D>F*_^j
YGFE(t;lPU
} 2NMS'"8
g-)izPX
@#m@ .
/* )nE=H,U?y
**FileAccess.java \JjZ _R
*//文件访问(定位，写) G(joamfM
package NetFox; 'b1k0 9'
import java.io.*; StZ GKY[Q
mu`:@7+Yp
}^3CG9%
public class FileAccessI implements Serializable{ X0G6Wp
>8%<ML
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CCx_|>
RandomAccessFile oSavedFile; XLQt>y)
long nPos; ul@G{N{L
lqdil l\
gkkT<hEV=
public FileAccessI() throws IOException -|_#6-9
{ X$mCn#8m
this("",0); %? 87#|
} V&e9?5@
&}}UdJ`
fib#)KE
public FileAccessI(String sName,long nPos) throws IOException d!>.$|b
{ vNo(`~]c
oSavedFile = new RandomAccessFile(sName,"rw"); T'C^,,if
this.nPos = nPos; 'Z;8-1M?O
oSavedFile.seek(nPos); :]]#X ~J
} X0\O3l*j
f)'mpp^
%BBM%Lj
public synchronized int write(byte[] b,int nStart,int nLen) ':fq/k3;&
{ VDy2!0
int n = -1; Kd,8PV*_
try{ K9G1>*
oSavedFile.write(b,nStart,nLen); ZH<:g6
n = nLen; oyfY>^bs
} 9Kl:3C
catch(IOException e) '\g-z
{ m+m2<|%x
e.printStackTrace (); t_ju[xL5B
} kn5X:@{
gdr"34%vbM
^\"@r%|
return n; ,/%@:Fh4
} SHcFnxEAIH
9Su4nt`i
;zF3e&e(
} VAD9mS^~
|!Ryl}Oi
Hs6?4cgj
/* E@} NV|90
**SiteInfoBean.java YmwUl>@{
*/ }.DE521u
package NetFox; PPpq"c
IJ[r!&PY
|^:qJ;dOP
public class SiteInfoBean { qnc?&f
Sj(5xa[
]0dj##5tJ
private String sSiteURL; //Site's URL uE'O}Y95
private String sFilePath; //Saved File's Path b@s6jNhVO^
private String sFileName; //Saved File's Name ./l^Iz&0
private int nSplitter; //Count of Splited Downloading File v^0*{7N'
=%=lq0GF0
&hnI0m=X
public SiteInfoBean() @yImR+^.7
{//nSplitter的缺省值为5 iY[+BI:
//default value of nSplitter is 5 3bU(ea^e$
this("","","",5); Bz+zEXBC
} R"2wop
%$Smei
5|<jPc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ](@HPAG]
{ kN~:Bh$
sSiteURL= sURL; d}:eLC
sFilePath = sPath; <6rc8jYz
sFileName = sName; [aS<u`/g|
this.nSplitter = nSpiltter; R]LuZN
fFe{oR
rGDx9KR4K!
} T%Nm
'-KYeT\;
14DHU
public String getSSiteURL() 5Q$.q&,
{ iZ( U]
return sSiteURL; wJAJ /
} *DUP$@}k
=:"wU
gVscdg5
public void setSSiteURL(String value) je#OV,uHM
{ !E@4^A80\W
sSiteURL = value; UURYK~$K:
} `qs[a}%'>"
oE.59dx
a #`Y(R'
public String getSFilePath() G2y`yg
{ ?h|&kRq
return sFilePath; 6k9cvMs%H
} S*3*Q l*
&l8eljg
}nx5
public void setSFilePath(String value) 1Qk]?R/DN
{ ,L&d\M"f
sFilePath = value; $o%:ST4
} % |^V)
pf8M0,AY
(ebC80M
public String getSFileName() `EdZ
{ q).["fSV
return sFileName; FGey%:p9$
} <y2HzBC
GoUsB|-\
[X"pOz
public void setSFileName(String value) YwizA}a#
{ o|V`/sW{
sFileName = value; % B^BN|r
} P _x(`H
`i5\(cdl
MLT^7'y
public int getNSplitter() UP .4#1I
{ r "uQ|
return nSplitter; IY"+hHt
} |>zYUT[V
80GBkFjV
M* 0zvNg
public void setNSplitter(int nCount) HT%'dZ1
{ w.o>G2u
nSplitter = nCount; K6EG"Vv!
} 'ju'O#A9
} }bZb8hiG
Ly P Cc|
?#~km0~F)
/* K41Gn
**Utility.java aoHAB<.C
*/ y!M# #K*
package NetFox; OPuty/^!Gw
SpC6dkxD\
[/Sk+ID
public class Utility { I} .9
s H(io
]|_UpP8EP
public Utility() &dky_H
{ 6o)RsxN eu
)#l&BV5
-P:o ^_)g
} eA_]%7+`
br,xwc
//线程睡眠 mFrDV,V
public static void sleep(int nSecond) `$t|O&z
{ D k<NlH zp
try{ c5(4rT{(m
Thread.sleep(nSecond); rrP_7D
} -q30tO.
catch(Exception e) 3}2;*:p4Y
{ lBzfBmEB
e.printStackTrace (); ><xJQeW
} eb>jT:
} lOy1vw'
<nU8.?\?~
//日志 {,B.OM)J
public static void log(String sMsg) Wud-(19
{ q8!X^1F7
System.err.println(sMsg); F4]=(T
} `-w,6
WX* uhR
8o i{%C&-
public static void log(int sMsg) VDFs.;:s
{ 1*f*}M
System.err.println(sMsg); 8?hZ5QvA(j
} &~:+2
} d7G DIYH<
Q9Vj8JO"{
4Opf[3]
/* 4I8QM&7
**TestMethod.java wvmcD%
*/ $It3}?>C'
package NetFox; BA8g[TA7K
3b?8<*
ye-[l7
public class TestMethod { zF@[S
qVW3oj<2
WK5B8u*<
public TestMethod() lhX4MB"
{ ///xx/weblogic60b2_win.exe >dJ[1s]
try{ 1i&|}"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u7SC_3R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VCzb[.
SiteFileFetch fileFetch = new SiteFileFetch(bean); G 2`hEX%
fileFetch.start(); ++ZP X'|
} a@^)?cH!z
catch(Exception e){e.printStackTrace ();} biG :Xn
@<3kj R?j
twhT6wz"
} >d(:XP6J
uO>pl37@
cB)tfS4)
public static void main(String[] args) pJJOy
{ lNz1|nS(Kd
new TestMethod(); Y;"jsK{$
} E|A~T7G=
} z.|[g$F
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