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)); Z<|x6%
} @B0fRG y
for(int i=0;i<nEndPos.length-1;i++) @8\0@[]
{ v3[ZPc;;
nEndPos = nStartPos[i+1]; Ew]&~:$Ki
} <>KQ8:
nEndPos[nEndPos.length-1] = nFileLength; +mG"m hF
} 5n>zJ ~
} WMKxGZg"
lre(]oBXA
\=RV?mI3?
//启动子线程 _H U>T
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {6LS$3}VM
for(int i=0;i<nStartPos.length;i++) !}|'1HIC
{ N\ <riS9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }qGd*k0F0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Lwtp,.)pR
nStartPos,nEndPos,i); ,I|^d.[2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "uZ^zV`"
fileSplitterFetch.start(); @=g{4(zR^
} r+Sv(KS4i^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Xr o5~G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Rex86!TO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *B4OvHi)'
nEndPos = " + nFileLength); *pO`sC>
// fileSplitterFetch[nPos.length-1].start(); = <A0;
~Q^.7.-T
hH$9GL{H
//等待子线程结束 ~d<&OL
//int count = 0; tHqa%
//是否结束while循环 Jl\U~i
boolean breakWhile = false; 0f_`;{
GS>YfJ&DZ
.5SYN-@
while(!bStop) "8)%XSb
{ _TdH6[9
write_nPos(); K d#(eGe
Utility.sleep(500); ~"bBwPI
breakWhile = true; ?Z!R
qz)KCEs
"KCG']DF
for(int i=0;i<nStartPos.length;i++) I=Y_EjZD
{ C5KUIOg
if(!fileSplitterFetch.bDownOver) kg(}%Ih
{ asQ^33g z
breakWhile = false; SPe%9J+
break; cAx$W6S
} (uHyWEHt
} _^?_Vb
if(breakWhile) nql{k/6
break; #$ka.Pj
HOPl0fY$L
VeEa17g&
//count++; ,<7HLV
//if(count>4) \ %xku:
// siteStop(); `p)U6J
} 25 U+L
-oZw+ge}
T#e|{ZCbq
System.err.println("文件下载结束！"); N3Q .4? z9
} Ii3F|Vb G
catch(Exception e){e.printStackTrace ();} ]T40VGJ:h
} y9T5
<v\$r2C*
r_8;aPL
//获得文件长度 FBrh!vQ<
public long getFileSize() 3k8nWT:wT
{ dBM{]@bZ
int nFileLength = -1; ^;{uop"DS
try{ Y#P!<Q>}
URL url = new URL(siteInfoBean.getSSiteURL()); +s7w@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jMX+uYx M
httpConnection.setRequestProperty("User-Agent","NetFox"); G `eU
>,Zn~8&Z
CCC9I8rZD
int responseCode=httpConnection.getResponseCode(); #l*w=D?
if(responseCode>=400) M)JozD%
{ [k%u$
processErrorCode(responseCode); $E8}||d
return -2; //-2 represent access is error C%%gCPI^y
} k:mW ,s|a
:"nh76xg<
Ew;AYZX
String sHeader; l"h6e$dP
rNm_w>bq
L6jwJwD
for(int i=1;;i++) 2H] 7=j
{ FUL'=Xo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); M`9|8f,!a
//Utility.log(in.readLine()); |<8Fa%!HHc
sHeader=httpConnection.getHeaderFieldKey(i); VV[Fb9W ;
if(sHeader!=null) M4 }))
{ 5+b73R3r
if(sHeader.equals("Content-Length")) RA){\~@wC
{ 6#:V3 ;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j5smmtM`s
break; Vvv;m5.
} Ofb&W AD
} YoK )fh$
else 9B>P Qbs
break; WFmW[< g
} 3:c6x kaw
} cUw$F{|W
catch(IOException e){e.printStackTrace ();} V~-tp^
catch(Exception e){e.printStackTrace ();} ^%\MOjSN
R9K~b^`
_Wp.s]D [
Utility.log(nFileLength); " w /Odd
E2=vLI]
tp"eXA0n
return nFileLength; ]Ee$ulJ02
} eT2Tg5Etc
s I0:<6W
`4Fw,:+e
//保存下载信息（文件指针位置） M`* BS
private void write_nPos() fCX8s(|F
{ JPZH%#E(
try{ # xX
output = new DataOutputStream(new FileOutputStream(tmpFile)); B oiS
output.writeInt(nStartPos.length); CLuQ=-[|
for(int i=0;i<nStartPos.length;i++) :S-{a
{ #B!M,TWf9s
// output.writeLong(nPos); k2#|^N
output.writeLong(fileSplitterFetch.nStartPos); U{@2kg-
output.writeLong(fileSplitterFetch.nEndPos); (*T$:/zIS
} UQP>yuSx
output.close(); fL-$wK<p<
} Vhe$vH
catch(IOException e){e.printStackTrace ();} ,sg\K>H=
catch(Exception e){e.printStackTrace ();} [4yw? U
} P*ZMbAf.
:+?rnb)N
93,7yZ5#
//读取保存的下载信息（文件指针位置） q(2ZJn13f
private void read_nPos() %z~kHL
{ \zDs3Hp
try{ hdmKD0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7^d7:1M
int nCount = input.readInt(); \W\*'C8q\
nStartPos = new long[nCount]; Bf[`o<c
nEndPos = new long[nCount]; &2ty++gC
for(int i=0;i<nStartPos.length;i++) gC_KT,=H;
{ N&$ ,uhmO
nStartPos = input.readLong(); {#pwrWG
nEndPos = input.readLong(); :FmH=pI!=
} Wn?),=WQ{
input.close(); r{*BJi.b
} (Y^tky$9
catch(IOException e){e.printStackTrace ();} Y%}N@ ,lT
catch(Exception e){e.printStackTrace ();} bV"t;R9
} H%}/O;C
|tse"A5Z
rrphOG
private void processErrorCode(int nErrorCode) QTN'yd?WE
{ vbG&F.P
System.err.println("Error Code : " + nErrorCode); 43O5|8o
} i;juwc^n}
ID{XZ
$++O@C5
//停止文件下载 -]n%+,3L
public void siteStop() y(^\]-fE
{ W|s";EAM
bStop = true; M7&G9SGZ
for(int i=0;i<nStartPos.length;i++) i;29*"
fileSplitterFetch.splitterStop(); hR.vJ2oa
5/CF_v
RU>qj *e
} @Q;s[Kg{!
} 59+KOQul6
//负责部分文件的抓取 ":GC}VIS
**FileSplitterFetch.java mGkQx -|
*/ uW!saT5o
package NetFox; #nAq~@X
jCIY(/
[r'A8!/|[
import java.io.*; Jz P0D'
import java.net.*; Cbm^: _LR
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public class FileSplitterFetch extends Thread { :l?mNm5
ojA!!Ru
}Fox
String sURL; //File URL ^r mQMjF
long nStartPos; //File Snippet Start Position <~:2~r
long nEndPos; //File Snippet End Position T4[/_;1g
int nThreadID; //Thread's ID 1083p9Uh
boolean bDownOver = false; //Downing is over ovDPnf(
boolean bStop = false; //Stop identical d9%P[(yM^
FileAccessI fileAccessI = null; //File Access interface j9vK~_?;
[8 H:5Ho
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6GqC]rd*:
{ $ \o)-3
this.sURL = sURL; tvq((2
this.nStartPos = nStart; F!*GrQms
this.nEndPos = nEnd; ?zbWz=nq
nThreadID = id; wkV'']= Xg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 es=OWJt^
} Ki&a"Fu3
-*Th=B-
9QL%q; #
public void run() _-9cGm v
{ DQaE9gmC
while(nStartPos < nEndPos && !bStop) 1-&L-c.
{ fc[_~I'
j['B9vG
Z_Y'#5o#
try{ ~l*<LXp8
URL url = new URL(sURL); x($Djx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uU^iY$w
httpConnection.setRequestProperty("User-Agent","NetFox"); 0'YJczDq:7
String sProperty = "bytes="+nStartPos+"-"; mm.%Dcn
httpConnection.setRequestProperty("RANGE",sProperty); NSH4 @x
Utility.log(sProperty); ~-B+7
zgH*B*)bj
4??LK/s*
InputStream input = httpConnection.getInputStream(); X>P|-n#
//logResponseHead(httpConnection); ^5(d^N
5O Y5b8
%/5Wj_|p
byte[] b = new byte[1024]; _mwt{D2r}
int nRead; M CP GDr
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y\Utm$)j
{ XD't)B(q
nStartPos += fileAccessI.write(b,0,nRead); 1xkrhqq
//if(nThreadID == 1) ZmNNR 1%/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p(8@
} XrWWV2[
2A:h&t/|C
$$"G1<EZ
Utility.log("Thread " + nThreadID + " is over!"); 3JkdPh
bDownOver = true; a/1;|1a.
//nPos = fileAccessI.write (b,0,nRead); 5Dz$_2oM3
} sf->8
catch(Exception e){e.printStackTrace ();} Bx#=$ka
} _{gqi$Mi
} 2gMG7%d
GNq f
bovAFdHW
//打印回应的头信息 M}f(-,9
public void logResponseHead(HttpURLConnection con) CjP<'0gT
{ r@bh,U$
for(int i=1;;i++) T#*H
{ zNdkwj p+
String header=con.getHeaderFieldKey(i); ASre@pW
if(header!=null) 5,g +OY=\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v\@RwtP
Utility.log(header+" : "+con.getHeaderField(header)); FF!PmfF'
else ela^L_NhF
break; mtn^+*
} evYn}
} J%M [8
6)P.wW
GQ>0E
public void splitterStop() ~1[n@{*:(
{ w`V6vYd@
bStop = true; 7v)p\#-
} ;FRUB@:
#8yo9g6
Jp+'"a
} NRx I?v
-)VjjKz]8
Lhe&
/* y_=y%
**FileAccess.java #kq!{5,
*//文件访问(定位，写) x\8|A
package NetFox; 3}F>t{FDk
import java.io.*; Q}KOb4D
Jou*e%
!2l2;?jM
public class FileAccessI implements Serializable{ T,1qR:58
+>K&zS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i/1$uQ
RandomAccessFile oSavedFile; >7%T%2N
long nPos; yNP4Ey
V-n{=8s
zqXF`MAB=
public FileAccessI() throws IOException gu[EYg
{ r9'[7b1l
this("",0); j-W$)c3X
} `Hlf.>b1
emK*g<]
.hR <{P
public FileAccessI(String sName,long nPos) throws IOException #~"IlBk\
{ ,_Bn{T=U
oSavedFile = new RandomAccessFile(sName,"rw"); NR1M W^R
this.nPos = nPos; k4{|Xn
oSavedFile.seek(nPos); ]rH[+t-
} ?X@[ibH6
H?J:_1
x5BS|3W$a
public synchronized int write(byte[] b,int nStart,int nLen) X3kFJ{
{ F}ATY!
int n = -1; )`f-qTe
try{ ~ILv*v@m
oSavedFile.write(b,nStart,nLen); >19s:+
n = nLen; \\#D!q*
} UGy3B)
catch(IOException e) to</
{ ,.>9$(s
e.printStackTrace (); C9sU^]#F
} Vb\g49\o/
dB0#EJaE
!V3+(o1
return n; :VZS7$5
} ~io.TS|r
[Tp?u8$p`
Zja3HGL
} AG=PbY9
0P9\;!Y
dR1IndZl
/* *YvtT(Gt
**SiteInfoBean.java ;'8P/a$
*/ d\]KG(T
package NetFox; H/x0'
x"e;T,c
IONo&~-l
public class SiteInfoBean { vjx'yh|
*$fM}6}
[1P_^.Htr
private String sSiteURL; //Site's URL 8:V,>PH
private String sFilePath; //Saved File's Path z}u`45W+
private String sFileName; //Saved File's Name !~~KM?g
private int nSplitter; //Count of Splited Downloading File &kmaKc
*af\U3kx
S W%>8
public SiteInfoBean() bXF8V
{//nSplitter的缺省值为5 c-XO}\?
//default value of nSplitter is 5 >jhcSvM6
this("","","",5); mnK<5KLg1
} JR.)CzC
xOj#%;
v.Bwg7R3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A&t8C8,
{ `+n#CWZ"Y
sSiteURL= sURL; 8$_{R!x
sFilePath = sPath; <1*.:CL"s
sFileName = sName; \#: W
this.nSplitter = nSpiltter; *eIX"&ba
8p%0d`sX
SQ4^sk_!
} g]?pY
zl:by?
6LCtWX
public String getSSiteURL() p7Wt(A
{ }vZf&ib-
return sSiteURL; )Y)_T&O
} q=5aHH% |
+\Jo^\
it\$Pih]
public void setSSiteURL(String value) O~V^]
{ IdAh)#) 7
sSiteURL = value; yO%^[c?
} ?m]vk|>
Dnw^H.
{. 9BG&
public String getSFilePath() auK9wQ%\
{ by @qg:
return sFilePath; @iuX~QA[9
} :k1?I'q%
azv173XZ
)v_Wn[Y.H
public void setSFilePath(String value) T"vf
{ 7wx=#
sFilePath = value; G|Et'k.F4
} VU,G.eLW
#wIWh^^ Zy
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public String getSFileName() g,JfT^
{ \[3~*eX6
return sFileName; h6D4CT
} )mm0PJF~q
_{k*JT2
>B0AJW/u
public void setSFileName(String value) QNx]8r
{ }qECpKa0
sFileName = value; 6}E>B{Y
} yk?bz
R%RbC!P
>JE+j=
public int getNSplitter() T4.wz 58
{ ;99oJD,
return nSplitter; N E9,kWI
} qK.(wFx
,gQl_Amvz
uxTgK'3
public void setNSplitter(int nCount) <7U~0@<Y
{ b&[".ibN1
nSplitter = nCount; &!/>B .
} )^o.H~Pv
} .|[{$&B
YgcW1}
eWAD;x?.
/* `qs,V
**Utility.java I+kAy;2
*/ S~aWun
package NetFox; K-k!':K:
<Tgy$Hm
ulsU~WW7r
public class Utility { 9{;L7`<
#8et91qw
`r1}:`.m,
public Utility() 3!p`5hJd
{ s;TB(M~i[
(%L/|F_
>M2~p&Si
} !}h) |
>S:(BJMo
//线程睡眠 \bdKLcKI,
public static void sleep(int nSecond) *`+zf7-f
{ EX_j|/&tZ
try{ cQt&%SVT]E
Thread.sleep(nSecond); ~NK $rHwi%
} rlKR <4H
catch(Exception e) Y ]()v
{ [M[#f&=Z
e.printStackTrace (); jOfG}:>e\
} 9DA|;|
} P'8RaO&d
A^z{n/DiL
//日志 Py v>
public static void log(String sMsg) ~4~r
{ 0`S{>G
System.err.println(sMsg); *MmH{!=
} 5oG~Fc
}lp37,
Uwkxc
public static void log(int sMsg) l3Zi]`@r
{ C%Lr3M;S'
System.err.println(sMsg); tR>zBh_b
} "YI,
} W_M#Gi/AL
nvndgeSy
P0}B&B/a:
/* .hx(9
**TestMethod.java E\/[hT
*/ #[jS&rr(
package NetFox; 4x)vy-y
1+*sEIC"
5/nL[4Z
public class TestMethod { 2ul8]=
HU>>\t?d
m)L50ot:/
public TestMethod() ."ZG0Zg
{ ///xx/weblogic60b2_win.exe rNV3-#kU
try{ 5c::U=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [voZ=+/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~Fh+y+g?
SiteFileFetch fileFetch = new SiteFileFetch(bean); +ytP5K7
fileFetch.start(); F62 uDyY
} RWR{jM]V
catch(Exception e){e.printStackTrace ();} 5?$MZaT
_R ]s1
&7\}Sqp
} wIi(\]Q
y]yl7g =~
t)W=0iEd9
public static void main(String[] args) jm%s#`)g
{ 9jImuSZ
new TestMethod(); f%EHzm/V
} *xxk70Cb
} -*mbalU,J
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