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)); eVL#3|=
} ${(v Er#}k
for(int i=0;i<nEndPos.length-1;i++) a1p Z{Od
{ uw'>tb@
nEndPos = nStartPos[i+1]; ><<(6
} Lhg4fuos@)
nEndPos[nEndPos.length-1] = nFileLength; &PY~m<F
} 0$RZ~
} }xZR`xP(
+NML>g#F~z
ra87~kj<
//启动子线程 8 xfn$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y0nnn
for(int i=0;i<nStartPos.length;i++) pq8XCOllXx
{ ;U7o)A;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9a\H+Y~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ziclw)
nStartPos,nEndPos,i); r6 k/QZT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m]C|8b7Y
fileSplitterFetch.start(); OIi8x? .~]
} pib i#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W 7xh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F"p7&e\W|l
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &BF97%E2
nEndPos = " + nFileLength); 2~`lvx
// fileSplitterFetch[nPos.length-1].start(); MNC=r?
_=%F6}TE
>"LHr&;m&h
//等待子线程结束 \X3Q,\H @
//int count = 0; Uh6LU5
//是否结束while循环 ;Fo%R$y
boolean breakWhile = false; :/rl \woA>
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%"<|u)E
while(!bStop) &,v-AL$:Q
{ #}M\ J0QG
write_nPos(); -DVoO2|Dv
Utility.sleep(500); G909R>
breakWhile = true; *R'r=C`
,W8EU
=g.R?H8cj5
for(int i=0;i<nStartPos.length;i++) ;$a+ >
{ `efC4#*!!
if(!fileSplitterFetch.bDownOver) fAEgrw%Ti
{ q fc:%ks2
breakWhile = false; 1iA0+Ex(j
break; (M0"I1g|w
} \eF_Xk[
} <QuIXA
if(breakWhile) ~^{>!wU+
break; nrBpq
^_4e^D]P"
G_m$?0\
//count++; %IA1Y>`
//if(count>4) J#>)+
// siteStop(); [Xa,|
} g2LY~
jj,CBNo(
^4 MJ
System.err.println("文件下载结束！"); D%`O.2T Y|
} `w6*(t:T
catch(Exception e){e.printStackTrace ();} TdU'L:<4l
} 3 as~yF0
opXxtYC@
d/8p?Km
//获得文件长度 )_&P:;N
public long getFileSize() ndmsXls
{ bIWSNNV0F
int nFileLength = -1; JpRn)e'Z
try{ 4Wd H!z
URL url = new URL(siteInfoBean.getSSiteURL()); JRw<v4pZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ao )\/AR'
httpConnection.setRequestProperty("User-Agent","NetFox"); \?D~&d,a=
1^ijKn@6
"u.'JE;j
int responseCode=httpConnection.getResponseCode(); xA'RO-a}h
if(responseCode>=400) HUFm@?
{ .9u0WP95
processErrorCode(responseCode); @*16agGg
return -2; //-2 represent access is error 9bQD"%ha=d
} :hBLi99 o
S.zY0
>"q?P^f/
String sHeader; hS 9^Bi
b$eN]L
~} 02q5H
for(int i=1;;i++) `t>A~.f
{ [$DI!%e|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #AR$'TE#
//Utility.log(in.readLine()); dHkI9;
sHeader=httpConnection.getHeaderFieldKey(i); 0;L.h|R T(
if(sHeader!=null) cGSG}m@B`
{ y&W3CW\:
if(sHeader.equals("Content-Length")) KY%LqcC
{ n%ypxY0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); a)8;P7
break; 0<XxR6w
} <74r
} V}MRdt7
else I&%KOe0
break; Eb7GiRT#
} "$nff=]
} nh]HEG0CZJ
catch(IOException e){e.printStackTrace ();} eMLcmZJR
catch(Exception e){e.printStackTrace ();} FN<Sagj
C)mR~Ey
=`k',V_
Utility.log(nFileLength); Ov#G7a"
U;=1v:~d
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return nFileLength; 6 u1|pX8
} r+usMF<'
#0:rBKm,
/?1^&a
//保存下载信息（文件指针位置） [a!)w@I:
private void write_nPos() ]m :Y|,:6
{ n= q7*<l
try{ 6@;sOiN+
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,FwJ0V
output.writeInt(nStartPos.length); HF<h-gX
for(int i=0;i<nStartPos.length;i++) X>i{288M3
{ cAn_:^
// output.writeLong(nPos); A[`2Mnj
output.writeLong(fileSplitterFetch.nStartPos); P}"T3u\N
output.writeLong(fileSplitterFetch.nEndPos); 2Z-QVwa*U
} N<O<wtXIj
output.close(); T7^?j :kJ/
} }LY)FT4n
catch(IOException e){e.printStackTrace ();} Dqc2;>
catch(Exception e){e.printStackTrace ();} bZ#5\L2
} >uxAti\
-6xh
tHEZuoi
//读取保存的下载信息（文件指针位置） I9<%fv
private void read_nPos() @V Sr'?7-
{ :_h#A}8Xd
try{ Fd#Zu.Np
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); VV/aec8
int nCount = input.readInt(); 4+Jf!ovS=
nStartPos = new long[nCount]; mRy0zN>?
nEndPos = new long[nCount]; ,hWuAu6.L
for(int i=0;i<nStartPos.length;i++) {mB!mbr
{ }S;A%gYm
nStartPos = input.readLong(); M}$Td_g
nEndPos = input.readLong(); 7u:QT2=&
} tF6-@T\6
input.close(); pM~-o?
} }tQ^ch;Q
catch(IOException e){e.printStackTrace ();} L9]d$ r"
catch(Exception e){e.printStackTrace ();} y@r0"cvz9
} xX@9wNYD
pq:[`
dsg-;*%
private void processErrorCode(int nErrorCode) /CUBs!
{ Bh&dV%'
System.err.println("Error Code : " + nErrorCode); a+j"8tHu$
} R7A:K]iJ5
5n[''#D
Ed+jSO0
//停止文件下载 lx7]rkWo|a
public void siteStop() e|q~t {=9S
{ B}J0d
bStop = true; V{fG~19
for(int i=0;i<nStartPos.length;i++) yG;@S8zC
fileSplitterFetch.splitterStop(); mNsd&Rk'
agq4Zy
:x3xeVtY
} Yy;BJ_
} DPkH:X
//负责部分文件的抓取 tO?-@Qf/9<
**FileSplitterFetch.java f`iDF+h<6
*/ av_ +M;G
package NetFox; \uO^wJ}
h^,av^lg^
dkeMiLm
import java.io.*; 7GCxd#DJ
import java.net.*; 6 $`l
Xpt9$=d
qt6@]Y
public class FileSplitterFetch extends Thread { 0\,!
3#Iq5vT
D G|v'#
String sURL; //File URL D/=k9[b!
long nStartPos; //File Snippet Start Position LnM$@
long nEndPos; //File Snippet End Position =\mJ5v"hA
int nThreadID; //Thread's ID lPrAx0m13%
boolean bDownOver = false; //Downing is over [7NO !^
boolean bStop = false; //Stop identical ou{V/?rb
FileAccessI fileAccessI = null; //File Access interface o' v!83$L
{ `xC~B h
fWb+08}C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p 16+(m
{ +(W7hK4ip
this.sURL = sURL; D;*cy<_K8
this.nStartPos = nStart; ML0_Uc3en
this.nEndPos = nEnd; KzJJ@D*4M]
nThreadID = id; }0f~hL24
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RS#C4NG
} =pTTXo
j WMTQLE.
Z$B%V t
public void run() :G]t=vr1
{ 8'NT_NPNb
while(nStartPos < nEndPos && !bStop) x 0#u2j?zj
{ fwlicbs'
LOr(HgyC
hc|#JS2H@y
try{ _g-0"a{-
URL url = new URL(sURL); WQ9Q:F2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gVy`||z
httpConnection.setRequestProperty("User-Agent","NetFox"); U9*< dR
String sProperty = "bytes="+nStartPos+"-"; z`NJelcuz\
httpConnection.setRequestProperty("RANGE",sProperty); ;*ni%|K
Utility.log(sProperty); Wyow MFp
hztqZ:
w9mAeGyE
InputStream input = httpConnection.getInputStream(); [_}8Vv&6
//logResponseHead(httpConnection); Rf2mBjJ(z
Xbrc_V\_
WJ LqH<
byte[] b = new byte[1024]; }%<_>b\
int nRead; Mz86bb^J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VvT7v]
{ F,Ve,7kh
nStartPos += fileAccessI.write(b,0,nRead); Ix<!0! vk
//if(nThreadID == 1) UoUQ6Ij
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TtH!5{$s
} >_G'o
2E`mbT,v&
u:6R|%1fNn
Utility.log("Thread " + nThreadID + " is over!"); 2\1bQq\
bDownOver = true; ] W$V#
//nPos = fileAccessI.write (b,0,nRead); * dk(<g=fM
} JIHIKH-#
catch(Exception e){e.printStackTrace ();} $o9@ ?2
} WBA7G
} ^~6gkS }
iq^;csyKb
Koj9]2<0
//打印回应的头信息 B !wr}]
public void logResponseHead(HttpURLConnection con) uBn35%
{ Xr'b{&
for(int i=1;;i++) jSRi
{ UX<)hvKj
String header=con.getHeaderFieldKey(i); pf+VYZ#)
if(header!=null) tkkh<5{C
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r. (}
Utility.log(header+" : "+con.getHeaderField(header)); 7$t['2j3
else wA)nryXV
break; OVc)PMp
} 2-Wy@\
} euW
;t,v/(/3
3 TTQff
public void splitterStop() zSu,S4m_;
{ wXKt)3dmu
bStop = true; E7_OI7C
} '#eT
{E7STLQ_%
qmenj
} ,A)Z.OWOq
ET 0(/Zz
-YmIRocx
/* 2JcP4!RD
**FileAccess.java 8OO[Le]1
*//文件访问(定位，写) U0srwt97S
package NetFox; &\Lu}t7Ru
import java.io.*; ZLPj1L
9sd}Z,l
l4(FM}0X5}
public class FileAccessI implements Serializable{ &-X51O C
8V9OMOt!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [Fv,`*/sm
RandomAccessFile oSavedFile; 8.7q -<Q
long nPos; !^v~hD$_q
z|Yt|W
Df:/r%
public FileAccessI() throws IOException i1A<0W|
{ v-^tj}jA
this("",0); fakad#O
} t5u#[*
wu &lG!#
bNiJ"k<pN
public FileAccessI(String sName,long nPos) throws IOException r4fg!]J;
{ )0"T?Ivp]
oSavedFile = new RandomAccessFile(sName,"rw"); =6i+K.}e
this.nPos = nPos; o^//|]H3Y
oSavedFile.seek(nPos); F- u"zox
} H*P+>j&
Zk>m!F>,p
a/3'!}&e
public synchronized int write(byte[] b,int nStart,int nLen) t~nW&]E
{ T!HAE#xC
int n = -1; :nc%:z=O
try{ /=A@O !l
oSavedFile.write(b,nStart,nLen); rmtCCPF?0
n = nLen; [?;L
} ! hEZV&y
catch(IOException e) nZc6 *jiz
{ m_BpY9c]5
e.printStackTrace (); 7Kb&BF|Q
} C8)Paop$
Aayd3Ph0%
1$6 u
return n; 51H6 W/$
} |W@Ko%om
{?EmO+![}
|$ZS26aYw}
} ZM<UiN
81(\8#./
sG[qlzR=8
/* J$sp6g>K
**SiteInfoBean.java 'zT7$ .L
*/ a|#pl!
package NetFox; 1 XJZuv,T:
4xg1[Z%:
Bss*-K]
public class SiteInfoBean { oIIi_yc
OYn5k6
RL/7>YQ
private String sSiteURL; //Site's URL ua &uR7
private String sFilePath; //Saved File's Path 1/qD5 *`Y
private String sFileName; //Saved File's Name 8ph1xQ'
private int nSplitter; //Count of Splited Downloading File pY&dw4V
?hR0 MnP
8m `Y
public SiteInfoBean() aG4 ^xOD
{//nSplitter的缺省值为5 zb02\xvf
//default value of nSplitter is 5 6c/0OM#
this("","","",5); f~TkU\Rh
} 2Ur&_c6P
Aw4)=-LKO
x_?K6[G&}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~i'!;'-_}
{ ="%887e
sSiteURL= sURL; "&^KnWk=
sFilePath = sPath; 7^UY%t
sFileName = sName; _v,Wl/YAp
this.nSplitter = nSpiltter; T g3MPa#g
&TrL!9FtJ
>1]hR)Ip
} sCQV-%9
^T1caVb|>
Us2> 5 :\
public String getSSiteURL() ,1JQjsR
{ B9cWxe4R#
return sSiteURL; t7xJ"
} /d Ua
) .' + {
*8yC6|wL?
public void setSSiteURL(String value) qD=b+\F
{ M 0RA&
sSiteURL = value; B,Tv9(sv
} *-q&~
]W~M?1}
!bnnUCTb\
public String getSFilePath() H!6&'=c{k
{ tI#65ox#
return sFilePath; 2bw.mp&v1
} p:{L fQ
o54=^@>O<j
xcQ^y}JN
public void setSFilePath(String value) D(dV{^} 9
{ oY,{9H37b
sFilePath = value; >qO l1]uF
} BC1smSlJ
;4/ n~
k+je-%hPj
public String getSFileName() erTly2-SJ
{ 5xNOIOpDB
return sFileName; a[sdYZ
} -O/[c
V2@(BliP
~Hj c?*
public void setSFileName(String value) +2Aggv>*
{ ;G"!y<F
sFileName = value; jO*H8XO
} Qx!Bf_,J
Y(EF )::
FJ?]|S.?,
public int getNSplitter() 8. +f@wv
{ N}{V*H^0QU
return nSplitter; EBQ_c@
} .N\t3\9}
7X>@r"9<
@$$J}~{
public void setNSplitter(int nCount) gf4Hq&Rf
{ qvhG^b0h
nSplitter = nCount; Ep')@7^n
} bun_R-
} /6\uBy"Xt
?@Tsd@s~r
Yc3\
/* o@aXzF2
**Utility.java _ |HA\!
*/ $`0,N_C<}
package NetFox; M;KeY[u
u3&#UN
=_Z.x&fi
public class Utility { j"zW0g!S
QAY:H@Gt:
+G7[(Wz(z
public Utility() 7suT26C
{ j-FMWEp
JPgFTr
#E<~WpP
} Cgf4E{\U!
1UB.2}/:
//线程睡眠 B/hQvA;(
public static void sleep(int nSecond) ?A*<Z%}1?
{ A4;~+L:M
try{ )2Y]A^Y
Thread.sleep(nSecond); A L|,\s
} w^3S6lK
catch(Exception e) U56g|V
{ "tpD ->
e.printStackTrace (); "(';UFa
} 6KN6SN$
} zd F;!
&Fk|"f+
//日志 X .K*</(g
public static void log(String sMsg) :inVwc
{ |^F$Ta
System.err.println(sMsg); j*1MnP3/8Y
} ^ ~Tn[w W_
;vpq0t`
W}(T5D" 3x
public static void log(int sMsg) j4=\MK
{ ;LKYA?=/V
System.err.println(sMsg); x&EMg!
} rO/Sj<0^
} b!"FM/%
0}9jl
k@[[vj|W
/* p2+K-/}ApP
**TestMethod.java k%s,(2)30
*/ {!.w}
package NetFox; O\%0D.HEz
v&f\ Jv7
{)Wa"|+
public class TestMethod { Rdj^k^V+a1
@x*,fk
>.XXB 5a
public TestMethod() x{rjngp2
{ ///xx/weblogic60b2_win.exe V%zo[A
try{ 0B~x8f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C}9|e?R[Rz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $!\L6;:
SiteFileFetch fileFetch = new SiteFileFetch(bean); n+vv %
fileFetch.start(); 5fmQ+2AC1
} ?PV@WrU>B
catch(Exception e){e.printStackTrace ();} $8[JL\
"`a,/h'
)$*B
} vP%:\u:{
#9qX:*>h
z> N73 u
public static void main(String[] args) 2Z`Jr/
{ "tA.`*
new TestMethod(); Pt6d5EIG
} _,p/2m-Pj
} : 'pK
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