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)); Miqu
} -<sn+-uE:
for(int i=0;i<nEndPos.length-1;i++) 3'Q H\t5
{ b{s_cOr/
nEndPos = nStartPos[i+1]; /K:M ,q
} Wu<
nEndPos[nEndPos.length-1] = nFileLength; 97e fWYj
} B%Dy;zdWd/
} lz EF^6I
$:s1x\ol
u}D.yI8
//启动子线程 bQow,vf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?3kfhR
for(int i=0;i<nStartPos.length;i++) K5z*DYT
{ Y<X%'Wd\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FJKt5}`8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o8BbSZVu
nStartPos,nEndPos,i); aAF:nyV~~0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WZ'8{XY8
fileSplitterFetch.start(); @a)@1:=Rm
} kYl$V=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _\>?.gg$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NQ !t`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,Ww)>O+
nEndPos = " + nFileLength); nM34zVy
// fileSplitterFetch[nPos.length-1].start(); "2}04b|"
;FQAL@"Yj
*qj @y'1\
//等待子线程结束 4Z"DF)+}
//int count = 0; W`^'hka
//是否结束while循环 pvQw+jX
boolean breakWhile = false; u1/4WYJeJ
:h=];^/E
2)h i(
while(!bStop) I1BVqIt1i
{ *L%HH@] %_
write_nPos(); F:x" RbbF
Utility.sleep(500); cP`f\\c
breakWhile = true; vr/V_
:"g^y6i
$SRpFz5y$
for(int i=0;i<nStartPos.length;i++) ] NL-)8u
{ GN?^7kI
if(!fileSplitterFetch.bDownOver) vXLiYWo
{ 63QMv[`,
breakWhile = false; f{FW7T}O2
break; y/h~oGxy
} {*ATY+
} D3$PvX[f
if(breakWhile) 3bu VU&ap
break; @bOhnd#W
EA|*|o4)
&Vg+n0
//count++; iUFS1SN \
//if(count>4) $Lv,e\]
// siteStop(); 7f#e#_sM;
} >K1)XP
M9HM:
_,"T;i
System.err.println("文件下载结束！"); O&V}T#8n
} O;9u1,%w
catch(Exception e){e.printStackTrace ();} *?Nrx=O*
} MzL^u8
*r@7:a5
b4ZZyw
//获得文件长度 QxH%4 )?
public long getFileSize() rS\j9@=Y4
{ fPZt*A__
int nFileLength = -1; $[T^S
try{ ' 7+x,TszI
URL url = new URL(siteInfoBean.getSSiteURL()); " JFx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %/"I.\%d
httpConnection.setRequestProperty("User-Agent","NetFox"); 9cp-Rw<tI
Urj8v2k
Xt^ldW
int responseCode=httpConnection.getResponseCode(); %%)"W n#`
if(responseCode>=400) >0DQ<@ot:
{ zUXQl{
processErrorCode(responseCode); I'HPy.PV
return -2; //-2 represent access is error Zy|B~.@<j
} D+P(
N9tH0
x2=Bu#Y
String sHeader; x^Q:U1
H<#M)8
bGOOC?[UX
for(int i=1;;i++) JS<S?j?*/
{ <qT[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?1*Ka
//Utility.log(in.readLine()); 0_q8t!<xJw
sHeader=httpConnection.getHeaderFieldKey(i); .T 6NMIp*
if(sHeader!=null) =e](eA;
{ Y<-h#_
if(sHeader.equals("Content-Length")) <K;
{ C]414Ibi
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *`Swv`
break; `ltc)$
} FM;NA{
} g5M=$y/H
else $s+/OgG4H
break; 45. -P
} v_mk{
} Y[)b".K
catch(IOException e){e.printStackTrace ();} S"'0lS
catch(Exception e){e.printStackTrace ();} ?!^ow5"8
O 7RIcU
,%"!8T
Utility.log(nFileLength); {,NGxqhE
JJ_b{ao<
3n;>k9{
return nFileLength; ]xC#XYE:dy
} w\,N}'G
Su?e\7aj
[p3{d\=*?
//保存下载信息（文件指针位置） uP, iGA
private void write_nPos() ( m/ujz
{ :B{Wf 2<z
try{ lC/1,Z/M
output = new DataOutputStream(new FileOutputStream(tmpFile)); |_."U9!Z^
output.writeInt(nStartPos.length); ?+av9;Kg
for(int i=0;i<nStartPos.length;i++) ze2%#<
{ *N>n5B2
// output.writeLong(nPos); n2}(Pt.
output.writeLong(fileSplitterFetch.nStartPos); >*s_)IH2
output.writeLong(fileSplitterFetch.nEndPos); EP,j+^RVf
} 0DtewN{Z
output.close(); EyR~VKbJ'
} '&hz*yk
catch(IOException e){e.printStackTrace ();} Ak3cE_*Y/
catch(Exception e){e.printStackTrace ();} j5m KJC
} !q\MXS($#u
]QKo>7%[
YBh|\
//读取保存的下载信息（文件指针位置） )U12Rshl
private void read_nPos() ~_Q~AOFM
{ $mxm?7ZVR
try{ hr$Wt?B
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }`KK
int nCount = input.readInt(); 5~D(jHY;
nStartPos = new long[nCount]; ebno:)
nEndPos = new long[nCount]; '8%jA$o\g
for(int i=0;i<nStartPos.length;i++) ;)~}/nR<a
{ PAng(tubl
nStartPos = input.readLong(); 8tfM,.]_i
nEndPos = input.readLong(); '41'Gn
} OQW%nF9~
input.close(); Kzwbr?&z
} "DaE(S&
catch(IOException e){e.printStackTrace ();} "&Hr)yyWG
catch(Exception e){e.printStackTrace ();} 1lo.X_
} Q$+6f,m#W
P:D;w2'Q
8\WV.+
private void processErrorCode(int nErrorCode) RW~!)^
{ mtU{d^B
System.err.println("Error Code : " + nErrorCode); {zX]41T
} |RjAp.pm
nQGl]2
]K?;XA3dZ
//停止文件下载 c wNJ{S+
public void siteStop() U#V&=~-
{ cWtuI(.
bStop = true; ES-V'[+jDy
for(int i=0;i<nStartPos.length;i++) T:T`M:C.
fileSplitterFetch.splitterStop(); e5RF6roxO
I(<9e"1O
/< k&[
} X)e#=w!fi3
} d|#&j."
//负责部分文件的抓取 |d$4Fu(M~
**FileSplitterFetch.java ?f}?I`S,
*/ 1aI&jdJk
package NetFox; r[?GO"ej5
$RH.
_(zZrUHB
import java.io.*; YMN=1Zuj?
import java.net.*; *+OS;R1<
|`ya+/ff+
?(Se$iTZ
public class FileSplitterFetch extends Thread { :V3z`}Rl
{Qi J-[q
:)Pj()Os|
String sURL; //File URL zu3Fi= |0
long nStartPos; //File Snippet Start Position H )51J:4
long nEndPos; //File Snippet End Position (> W\Nf
int nThreadID; //Thread's ID l~]D|92
boolean bDownOver = false; //Downing is over '-U&S
boolean bStop = false; //Stop identical ]p8zT|bv
FileAccessI fileAccessI = null; //File Access interface zmU@ k
SZ29B
r<$o [,W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4#CHX^De
{ >.M>,m\
this.sURL = sURL; y2W|,=Vd
this.nStartPos = nStart; nU4to
this.nEndPos = nEnd; Rk,'ujc
nThreadID = id; beaSvhPU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =t^jlb
} O1D|T"@
rFUR9O.{E
cJMi`PQ;
public void run() ?7>"ZGDe>
{ Ptz##o'{5
while(nStartPos < nEndPos && !bStop) fat;5XL@
{ 3eg6 CdT
^T:L6:
!&xci})7a
try{ G6QD`ED
URL url = new URL(sURL); fy]c=:EmD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jDb"|l
httpConnection.setRequestProperty("User-Agent","NetFox"); T|8:_4/l
String sProperty = "bytes="+nStartPos+"-"; <UF0Xc&X'
httpConnection.setRequestProperty("RANGE",sProperty); iC3C~?,7
Utility.log(sProperty); |Fz ^(US
o$eo\X?J?
;4U"y8PVTh
InputStream input = httpConnection.getInputStream(); l?QA;9_R'
//logResponseHead(httpConnection); +OqEe[Wk#
8>@JW]
jST4O"DjM
byte[] b = new byte[1024]; #dKy{Q3he
int nRead; Vm8@LA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) eF]8Ar1
{ CY*o"@-o5)
nStartPos += fileAccessI.write(b,0,nRead); -)Bvx>8fq-
//if(nThreadID == 1) MVnN0K4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >23$_'2
} *|<T@BXn
IU<lF)PF$
(i L*1f
Utility.log("Thread " + nThreadID + " is over!"); {G0=A~
bDownOver = true; c<,LE@V
//nPos = fileAccessI.write (b,0,nRead); NXQ=8o9,9
} -%5#0Ogh M
catch(Exception e){e.printStackTrace ();} re_nb)4g
} 81"` B2
} }K8e(i6z
LPBa!fq
Ui!l3_O
//打印回应的头信息 d)S`.Q
public void logResponseHead(HttpURLConnection con) RyP MzxV
{ I?St}Tl
for(int i=1;;i++) 5D.Sg;\
{ ~Th,<w*o
String header=con.getHeaderFieldKey(i); mogmr
if(header!=null) lP*n%Pn)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m";..V
Utility.log(header+" : "+con.getHeaderField(header)); 9Vqy<7i1
else >s 6ye
break; .dMdb7
} V*ao@;sD
} 76"4Q!
r<vy6
VP>*J`'H
public void splitterStop() [zBi*%5O
{ a_+?#m
bStop = true; y+T[="W
} 9@ YKx0
zBlv?JwG
Cdib{y<ji
} ax>j3HKi
m3BL
5L:-Xr{
/* jQzl!f1c3
**FileAccess.java Db<#gH
*//文件访问(定位，写) @J&korU
package NetFox; X3a9-
import java.io.*; 'prHXzi(h
%0}^M1
c\2rKqFD8
public class FileAccessI implements Serializable{ g\fj6
);':aXj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +^lB"OcOX@
RandomAccessFile oSavedFile; ?WHf%Ie2(
long nPos; #H w(w
iX6>u4~(
Vn4wk>b}$2
public FileAccessI() throws IOException E0R6qS:'
{ *s*Y uY%y
this("",0); ')!X1A{
} Oo@o$\+v
i4,p\rE0
BH1h2OEe#
public FileAccessI(String sName,long nPos) throws IOException w^ut,`yWR
{ Jr( =Y@Z'
oSavedFile = new RandomAccessFile(sName,"rw"); VO8rd>b4
this.nPos = nPos; jOVF+9M
oSavedFile.seek(nPos); cu($mjC@T
} xsB0LUt
vo`&
O`c50yY
public synchronized int write(byte[] b,int nStart,int nLen) Hl0" zS[
{ =K18|Q0m
int n = -1; E{&MmrlL,
try{ .a]#AFX
oSavedFile.write(b,nStart,nLen); -1,0hmn=+
n = nLen; /3,Lp-kp
} >PSO]%mE
catch(IOException e) q:/df]Ntt
{ 4lB??`UN
e.printStackTrace (); /W$i8g
} =&}_bd/]
/j$=?Rp
D<;~eZ'
return n; <;S$4tux
} ![^pAEgx
YND}P9 h
VFL^-tXnA^
} "vSKj/]
NC%hsg^0/
4}h}`KZZ
/* yl~_~<s6
**SiteInfoBean.java ^~;ia7V&2
*/ +Cw_qS"=
package NetFox; \4q|Qno8
qK a}O*
GYfOwV!zB
public class SiteInfoBean { [|OII!"
P[WkW#
Gv&G2^
private String sSiteURL; //Site's URL w!7ApEH1
private String sFilePath; //Saved File's Path @|SeabN^-
private String sFileName; //Saved File's Name t\K (zE
private int nSplitter; //Count of Splited Downloading File h6 {vbYj
Nv7-6C6<
}+9?)f{?@
public SiteInfoBean() KOS0Du
{//nSplitter的缺省值为5 H\Ra*EO~j
//default value of nSplitter is 5 8u+kA mI
this("","","",5); N s+g9+<A
} LigB!M
fz=?QEG
{siOa%;*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G kjfDY:
{ 172G
sSiteURL= sURL; 8|i'~BFHs
sFilePath = sPath; 4w^o !
sFileName = sName; yV!4Im.>
this.nSplitter = nSpiltter; 2bNOn%!
Cf=H~&`Z
[i`
} LpU}.
HU $"o6ap
=0=#M(w
public String getSSiteURL() q@ -B+
{ PC_!
return sSiteURL; 'w+]kt-
} 'dwT&v]@
-I|xW
0N,<v7PX
public void setSSiteURL(String value) s1D<R,J|H
{ JpC'(N
sSiteURL = value; 7y'":1
} R&Y_
< '5~p$
HY)xT$/J
public String getSFilePath() <:v+<)K
{ 8%7%[WC#
return sFilePath; KS$t
} _6NUtU
K3?5bT_{
Y<xqws
public void setSFilePath(String value) S/'0czDMW
{ a;HAuy`M x
sFilePath = value; E5&Z={
} :(n<c
|h]V9=
fg^25g'_
public String getSFileName() j>\c >U
{ r<UVO$N
return sFileName; AHb_BgOU*
} VL9wRu;
{]HiTpn
_Op%H)
public void setSFileName(String value) :jiuu@<
{ qVn<c,8#
sFileName = value; nje7?Vz
} |p6d]#z3
rwF$aR>9
TEC^|U`G
public int getNSplitter() c{=Sy;i@
{ $o[-xNn1
return nSplitter; J/je/PC
} &h334N|4{
hQn?qJy%W
*-T.xo
public void setNSplitter(int nCount) cE]z Tu?!
{ =}`d
nSplitter = nCount; ic2D$`M
} u&:N`f
} =l`)b
NIV}hf YF
b>07t!;
/* f7=MgFi
**Utility.java YXA@ c
*/ NHd@s#@
package NetFox; T~[:oil
hFIh<m=C?Y
cbJgeif
public class Utility { "V|Rq]_+%
V\L;EHtc$
is<:}z
public Utility() .vu7$~7
{ \o>-L\`O
/q9I^ztV
A,~3oQV
} B7%,D}
FuHBzBoM=
//线程睡眠 %ih\|jRt
public static void sleep(int nSecond) i KSRr#/
{ %N8I'*u
try{ f8Hq&_Pn
Thread.sleep(nSecond); ~apt,hl
} b'z $S+
catch(Exception e) C>Ik ;
{ 7hk)I`o65
e.printStackTrace (); |bnd92fvks
} ]v ${k
} A({czHLhN5
xs"i_se
//日志 h"`\'(,X
public static void log(String sMsg) fCY|iO0.t
{ #w{`6}p
System.err.println(sMsg); I{IB>j}8
} '.|}
1w>[&#7
y3oq{Z>
public static void log(int sMsg) |J&\/8Q
{ Cd%5XD^
System.err.println(sMsg); , 'pYR]3
} L ]')=J+
} KXPCkNIN!
i2qN 0?n
[c?0Q3F
/* ;As~TGiT
**TestMethod.java %S312=w
*/ C @Ts\);^
package NetFox; P y'BMk
Z518J46o
[+[W\6
public class TestMethod { y_WC"
Oc)n,D)0
:,8y8z$+
public TestMethod() ]j&m\'-s
{ ///xx/weblogic60b2_win.exe ioi/`iQR
try{ e9p/y8gC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >k @t.PeoV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?'V78N sA
SiteFileFetch fileFetch = new SiteFileFetch(bean); RRO@r}A!y
fileFetch.start(); 0}i 9`p
} lU1SN/'zx
catch(Exception e){e.printStackTrace ();} ?1\5X<|,
k5RzW4zq;
SzLlJUVX
} |r@;ulO
O@$>'Z
2-F7tcya|
public static void main(String[] args) xU\!UVQ/
{ /E6)>y66
new TestMethod(); r6S
} TXB!Y!RG#
} Z_ElLY
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