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)); ^yiRrcOo
} [_ESR/&N
for(int i=0;i<nEndPos.length-1;i++) c*ac9Y'o
{ mjG-A8y
nEndPos = nStartPos[i+1]; * 3mF.^
} )2C`;\/:
nEndPos[nEndPos.length-1] = nFileLength; " cx\P,<
} %gDMz7$~
} ^.y}2
<hgt{b4
iqURlI);P
//启动子线程 ?)k;.<6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0m_c43+^
for(int i=0;i<nStartPos.length;i++) I:[^><?E
{ )xIk#>)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2ku\R7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +|MHiC
nStartPos,nEndPos,i); ]cLO-A
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hrPm$`
fileSplitterFetch.start(); Lh0Pvq0C
} vFXih'=_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @D&VOJV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9/TF#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;muxIr`?
nEndPos = " + nFileLength); m[,! orq
// fileSplitterFetch[nPos.length-1].start(); xpt*S~
8W Mhe=[
V~` ?J6
//等待子线程结束 XfmPq'#Z
//int count = 0; 57^X@ra$
//是否结束while循环 LC)-aw>-
boolean breakWhile = false; q-O=Em<*
.4pWyqU)!
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while(!bStop) ZAVjq;bq
{ Nw'i;}0v7r
write_nPos(); e*.l6H/B
Utility.sleep(500); 6VpT*,2d~
breakWhile = true; ^6`"f
<eKF
F Cg{!h
for(int i=0;i<nStartPos.length;i++) 9mfqr$3
{ E'zLgU)r`
if(!fileSplitterFetch.bDownOver) {(#Dou
{ H'Q4IRT
breakWhile = false; >QV=q`I
break; LO0<=4iN(
} h-<2N)>!
} :786Z,')
if(breakWhile) {[QCuR
break; zts%oIgV
HM ;9%rtO
Svj%O(
//count++; 1>bG]l1//
//if(count>4) F1%-IBe
// siteStop(); \zCT""'i
} =n|n%N4Y
vfPL;__{Y]
.XQ_,
System.err.println("文件下载结束！"); ;:NW
} `b 6j7
catch(Exception e){e.printStackTrace ();} ,,vl+Z<&
} YNV4w{>FD
qV2aa9p+
#]pFE.o
//获得文件长度 T7_i:HU%
public long getFileSize() oZTKG'
{ 45fk+#
int nFileLength = -1; zX{K\yp
try{ Y8YNRyc=
URL url = new URL(siteInfoBean.getSSiteURL()); [A99e`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ib8@U}Vn1
httpConnection.setRequestProperty("User-Agent","NetFox"); 7xidBVx
q_K8vGm4e
%7WGodlXW
int responseCode=httpConnection.getResponseCode(); *^+8_%;1
if(responseCode>=400) qELy'\
{ k_$:?$
processErrorCode(responseCode); ^F/gJ3_;
return -2; //-2 represent access is error `) s]T.-
} fH[Yc>(oj
^y"5pfSR
@%mJw u
String sHeader; Oo<L~7B
7kJ =C
luAmq+
for(int i=1;;i++) V*HkFT
{ x`/"1]Nf
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :s|" ZR
//Utility.log(in.readLine()); t_cNH@^3<3
sHeader=httpConnection.getHeaderFieldKey(i); 5lehASBz
if(sHeader!=null) _s{on/u
{ vqDd][n
if(sHeader.equals("Content-Length")) ";\na!MT
{ 5{?J5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z.EpRJn
break; ZdQt!
} .=rS,Tpo
} n@IpO i$Q
else ^)|8N44O
break; rbfP6t:c3
} "i3wc&9!?W
} ^5n"L29V
catch(IOException e){e.printStackTrace ();} Te&F2`vo
catch(Exception e){e.printStackTrace ();} fHK`u'
t;g=@o9YA
<49Gsm&0
Utility.log(nFileLength); M}Sn$h_
{uVvo=3
hfzmv~*
return nFileLength; |Et8FR3[m
} \/E+nn\)
M'gw-^(
Xtv^q>!
//保存下载信息（文件指针位置） M:&g5y&
private void write_nPos() RlJt+lnV
{ A|3'9iL{9
try{ !>gi9z,
output = new DataOutputStream(new FileOutputStream(tmpFile)); )nncCUW
output.writeInt(nStartPos.length); Rs*]I\
for(int i=0;i<nStartPos.length;i++) 4#jW}4C{
{ aPD4S&"Q
// output.writeLong(nPos); O2z{>\
output.writeLong(fileSplitterFetch.nStartPos); z^;0{q,
output.writeLong(fileSplitterFetch.nEndPos); IpX.ube
} y>4r<YZQ
output.close(); S3Q^K.e?
} `1;m:,9
catch(IOException e){e.printStackTrace ();} @APv?>$)
catch(Exception e){e.printStackTrace ();} Ll4/P[7:?
} =QG@{?JTl
QnHb*4<
4KH8dau.fF
//读取保存的下载信息（文件指针位置） Vqr#%.N
private void read_nPos() xw[KP [(
{ 4}C^s\?z
try{ 1< 22,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IY$v%%2WZ
int nCount = input.readInt(); C%#%_ "N
nStartPos = new long[nCount]; :x85:pa
nEndPos = new long[nCount]; `[.b>ztqgJ
for(int i=0;i<nStartPos.length;i++) |%p;4b
{ S}QvG&c
nStartPos = input.readLong(); \53(D7+
nEndPos = input.readLong(); njhDrwN
} O}$@|w(8;
input.close(); +hoZW R
} 6}b1*xQ
catch(IOException e){e.printStackTrace ();} e+`LtEve0
catch(Exception e){e.printStackTrace ();} {w/{)BnPG
} #J4{W84B
W|C>X=zTi
v2Lx4:dzi
private void processErrorCode(int nErrorCode) l~_]k
{ e+'PRVc
System.err.println("Error Code : " + nErrorCode); gXrXVv<)yw
} =t@8Y`9w
)Q:.1Hgl
e u{
//停止文件下载 L$T23*9XY
public void siteStop() BC*)@=7fx
{ 4gyC?#Ede
bStop = true; c:[z({`
for(int i=0;i<nStartPos.length;i++) I[P43>F3
fileSplitterFetch.splitterStop(); Ii*tux!S
hh%fmc
pK_n}QW
} Q:nBx[%
} 0j@nOj(3
//负责部分文件的抓取 #ZzFAt
**FileSplitterFetch.java aHhr_.>X
*/ |DB7o+4
package NetFox; ">-J+ST%
*/8b)I}yY
OD;-0Bj
import java.io.*; PIo8mf/
import java.net.*; p=fj1*
.k_> BD];
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public class FileSplitterFetch extends Thread { |"gg2p
)R~l@QBN
7IEG%FY T
String sURL; //File URL A(j9T,!
long nStartPos; //File Snippet Start Position oR``Jiob|
long nEndPos; //File Snippet End Position _lK+/"-l
int nThreadID; //Thread's ID aRt`IcZYz
boolean bDownOver = false; //Downing is over !Eqp,"ts7
boolean bStop = false; //Stop identical VXfp=JE
FileAccessI fileAccessI = null; //File Access interface F'NX
uD'GI
u*W6fg/"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /Soc,PjZ
{ Bz7rf^H`Z
this.sURL = sURL; G@.TE7a2Z
this.nStartPos = nStart; bi:TX<K+
this.nEndPos = nEnd; Ne!0`^`~
nThreadID = id; 6}q8%[l|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6ct'O**k*&
} +mgm39
Es7+bFvsE8
f!H~BMA+a
public void run() w!GPPW(
{ )qbjX{GZ7
while(nStartPos < nEndPos && !bStop) zw2qv'
{ L lNd97Z
Tgf\f%,h
AlVBhR`
try{ @N(*1,s2
URL url = new URL(sURL); NQ9/,M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cN?}s0
httpConnection.setRequestProperty("User-Agent","NetFox"); T_=IH~"
String sProperty = "bytes="+nStartPos+"-"; 3RbPc8($Y
httpConnection.setRequestProperty("RANGE",sProperty); neLQ>WT L
Utility.log(sProperty); ^KlW"2:
yJ0q)x sS
J*%XtRio
InputStream input = httpConnection.getInputStream(); 8.Z9 i
//logResponseHead(httpConnection); WP}NHz4H
$2><4~T;|A
j0X Jf<
byte[] b = new byte[1024]; >>>&{>}!
int nRead; bF"1M#u:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &"R`:`XF
{ 3D2\#6yo
nStartPos += fileAccessI.write(b,0,nRead); aN^x]0P!0
//if(nThreadID == 1) ]YF_c,Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y\C_HCU H
} #a$k3C
lx)Bj6
Q 1:7 9
Utility.log("Thread " + nThreadID + " is over!"); $~h\`vF&
bDownOver = true; Vw@?t(l>
//nPos = fileAccessI.write (b,0,nRead); gfPR3%EXs
} 'xG:v)(
catch(Exception e){e.printStackTrace ();} %fF0<c^-U
} eX0due
} A,u}p rwH
H,Y+n)5
G+SMH`h
//打印回应的头信息 xG7/[ jG
public void logResponseHead(HttpURLConnection con) 5Z<y||=
{ 0W6jF5T
for(int i=1;;i++) 5ltrr(MeD
{ 8TE2q Pm
String header=con.getHeaderFieldKey(i); ?TLzOYJp
if(header!=null) Y9w^F_relL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |ctcY*+
Utility.log(header+" : "+con.getHeaderField(header)); zF7*T?3b"
else yh'uH
break; N!Cy)HnS\w
} YD@n8?~$$
} LJ{P93aq`^
X$0&tmum
[AA*B
public void splitterStop() cvk$ I"q+
{ TGSkJ 1Lx
bStop = true; VJoobu1h
} p*Q *}V
XD8Q2un
sWGc1jC?.F
} GU,ztO.w3
?E6C|A$I
cq0#~20
/* ] v8.ym
**FileAccess.java Q|] 9
*//文件访问(定位，写) 1(`UzC=R|
package NetFox; Pe`eF(J
import java.io.*; M\!z='Fi
_9B ^@~
5f-eWW]!
public class FileAccessI implements Serializable{ tXg>R _\C
L Rn)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z<jH{AU
RandomAccessFile oSavedFile; iAn]hVW
long nPos; %h^ f?.(:
NN"!kuM
\ 0J&^C
public FileAccessI() throws IOException 8Rric[v
{ ?Mj@;O9>'
this("",0); 9J(jbJ7p
} Pq<]`9/w^w
)ePQN~#K}
lG/h[
public FileAccessI(String sName,long nPos) throws IOException 6b7SA,
{ KwxO%/-}S
oSavedFile = new RandomAccessFile(sName,"rw"); AD0pmD
this.nPos = nPos; cd3;uB4\,
oSavedFile.seek(nPos); |<Rf^"T
} zv>7;En3
_I<LB0kgf.
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public synchronized int write(byte[] b,int nStart,int nLen) /s|4aro
{ +)U>mm,
int n = -1; --BS/L-
try{ C/{%f,rU
oSavedFile.write(b,nStart,nLen); %]\IC(q
n = nLen; +/|t8zFWs
} V'm4DR#M
catch(IOException e) }0f"SWO>
{ s+7#TdhA
e.printStackTrace (); UR'P,
} rL3 f%L
G\ m`{jv
i8+[-mh
return n; tO8<N'TD
} /5&'U!:+
SMIr@*R
u0?,CQPL
} t(Sjo8, b
=1e>$E#
Y-y<gW
/* 9yWQ}h
**SiteInfoBean.java >j}.~$6dj_
*/ m6iQB\ \
package NetFox; =ec"G2$?"
|x/00XhS
uh 3yiDj@a
public class SiteInfoBean { |4?O4QN
M.h8Kr!.
w^N3Ma
private String sSiteURL; //Site's URL s;!Tz)
private String sFilePath; //Saved File's Path T$vDw|KSVP
private String sFileName; //Saved File's Name M_Z(+k{Gy
private int nSplitter; //Count of Splited Downloading File :}{,u6\
@q<F_'7is
m|%ly
public SiteInfoBean() l/:23\
{//nSplitter的缺省值为5 Ow f:Kife
//default value of nSplitter is 5 $5v:z
this("","","",5); rc()Eo50
} IuN:*P
0.kQqy~5
_YPu
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KoF_G[m
{ HCOE'24I
sSiteURL= sURL; Bq*aP*jv
sFilePath = sPath; ,o68xfdZVW
sFileName = sName; [_w;=l0 ;
this.nSplitter = nSpiltter; S*9qpes-m|
qdY*y&}"J
Udl8?EVSz
} %wk3&EC.
MFqM6_
/KLs+^c5
public String getSSiteURL() 9n!IdqKN
{ |a{~Imz{
return sSiteURL; gkRbb
} J%SuiT$L&Y
qEy]Rc%
jp|1S^b
public void setSSiteURL(String value) 8AQ@?\Rc"2
{ V+- ]txu|
sSiteURL = value; ml\2%07
} ._A@,]LS}
,bnrVa(I
Kh,zp{
public String getSFilePath() '%\FT-{
{ dRu|*s
return sFilePath; e=#'rDm
} NU{`eM
ocDAg<wo
]46#u=y~3
public void setSFilePath(String value) k<i#agq
{ LktH*ePO
sFilePath = value; ccm(r~lhJ
} s?pd&_kOv3
KV {J>J1
l0GsY.~,
public String getSFileName() :$5$H
{ 1$1[6 \3v
return sFileName; 22_%u=p-|
} hUO&rov3@
+:jx{*}jo
3Lw&HtH
public void setSFileName(String value) GT3?)g{Z
{ 4ht+u
sFileName = value; RI</T3%~
} +q-/~G'
K]s*rPT/,
,"U_oa3
public int getNSplitter() ?D8+wj
{ 5*P+c(=
return nSplitter; w_hN2eYo&e
} 6<>T{2b:(p
IwJ4K+
y3{F\K
public void setNSplitter(int nCount) ##_Jz5P
{ 6L4<c+v_
nSplitter = nCount; B?pNF+?'z
} T**v!Ls
} 4Ow0g-{
IqrT@jgN-
z [9f
/* '#Pg:v_
**Utility.java /.>8e%)
*/ {M&Vh]
package NetFox; "2 "gTS
i?0+f}5<p
k/]4L!/ T
public class Utility { ] lONi
e|2@z-Sp-
RP|/rd]-k
public Utility() \#O}K
{ guc[du
\Jy/ a-
}?KfL$@$
} ]sL)[o
K#_x.:<J
//线程睡眠 ecIZ+G)k
public static void sleep(int nSecond) & Y Y^Bd#
{ !wNj;ST*
try{ 'wm :Xa
Thread.sleep(nSecond); M`u&-6
} op5G}QZ
catch(Exception e) Tc.k0n%W:b
{ BK;Gh0mp
e.printStackTrace (); {.mPe|
} i0/RvrLc
} Pua|Z x
]~!?(d!J/
//日志 Al-;-t#Dc
public static void log(String sMsg) XMpa87\
{ & cV$`L
System.err.println(sMsg); , tb\^
} DITo.PU
Ae[Na:G+
{2,vxGi
public static void log(int sMsg) Z\. n6
{ _'Rzu'$`
System.err.println(sMsg); %8hjMds
} 05PRlz*x=
} P~d&PhOe
;:DDz
/|MHZ$Y9w?
/* LfsqtQ=J`
**TestMethod.java mtd ,m
*/ pEp`Z,p
package NetFox; 2*)2c[/0F
K~6,xZlDWM
rU!QXg]uD
public class TestMethod { 4#"_E:;PQ
HY!R|
ky#5G-X
public TestMethod() K*id 1YY
{ ///xx/weblogic60b2_win.exe |^k&6QO5
try{ (2uF<$7(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); z}z 6Vg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dgp1B\
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3[F9qDAy
fileFetch.start(); [@;q#.}Z
} ,*MAteD
catch(Exception e){e.printStackTrace ();} (<KFA,
w 8BSY
W{W8\
} 1LZ[i89&%
~;S
DV{0|E
public static void main(String[] args) }huFv*<@'
{ {'@`:p&3r
new TestMethod(); a2%xW_e
} M)6iYA%$
} B9(@.
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