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)); sdCG}..`
} V}<<?_
for(int i=0;i<nEndPos.length-1;i++) 9=iMP~?xF
{ )Rbt0
nEndPos = nStartPos[i+1]; S9l po_!z
} {}'Jr1
nEndPos[nEndPos.length-1] = nFileLength; YY tVp_)
} Y'P^]Q=}_#
} k~<Ozx^AyY
e^\(bp+83
]6v7iuvI
//启动子线程 xv$fw>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @(=?x:j
for(int i=0;i<nStartPos.length;i++) qOpwl*?x+
{ tOnOzD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /KnIU|;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o-_,l J7o^
nStartPos,nEndPos,i); *$VeR(QN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '.pGkXyQ
fileSplitterFetch.start(); ]5*H/8Ke7
} -ys/I,}<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dMjQV&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D8w.r"ne
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?\4kV*/Cqz
nEndPos = " + nFileLength); $Nvox<d0
// fileSplitterFetch[nPos.length-1].start(); )2W7>PY
-u~:Gd*l0
8%4v6No&*
//等待子线程结束 :+9. v
//int count = 0; k "7,-0gz
//是否结束while循环 EqD@o
boolean breakWhile = false; "S{GjOlEDF
g1F9IB42@<
nw*a?$S3
while(!bStop) {s*1QBM$\Z
{ ~a7@O^q4
write_nPos(); 4$2HO`@uN
Utility.sleep(500); T^d<vH
breakWhile = true; K\ pZ
?t\GHQ$$?
7w5l[a/
for(int i=0;i<nStartPos.length;i++) L28wT)D-
{ ; 1?L
if(!fileSplitterFetch.bDownOver) yP-$@Ry
{ Gl{2"!mt=
breakWhile = false; &u"mFweS
break; $@{d\@U
} &?@U_emLi
} fRk'\jzT
if(breakWhile) Wkb>JnPo
break; ~9!@BL\
9@M;\ @&g
AxJqLSfyb,
//count++; HWou&<EK
//if(count>4) OS L~a_
// siteStop(); Y~( 8<`^
} ;gJAxVD<
<|WXFjn
33}p02#
System.err.println("文件下载结束！"); 2}P{7flDY
} ~|{e"!(}
catch(Exception e){e.printStackTrace ();} 6eB~S)Ko
} V.Lk70 \
@Py'SH!-
I)%bOK]
//获得文件长度 [ot+EA
public long getFileSize() 6x!iL\Y~
{ FDGzh/
int nFileLength = -1; I L&PN`#
try{ u[wDOw
URL url = new URL(siteInfoBean.getSSiteURL()); ZZxt90YR'5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QRdtr
httpConnection.setRequestProperty("User-Agent","NetFox"); z:Ru`
(i<\n`h1K
==KDr0|G
int responseCode=httpConnection.getResponseCode(); VL\Ah3+
if(responseCode>=400) >W:kTS<
{ 2I=4l
processErrorCode(responseCode); )h(=X&(d
return -2; //-2 represent access is error KxJDAP
} WT 5 2
tC+11M
rP(;^8l"
String sHeader; +r"fv*g"
lYm00v6y
0|\A5 eG
for(int i=1;;i++) nGJ+.z
{ U; #v-'Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 33"!K>wC
//Utility.log(in.readLine()); =ZV+*cCC=q
sHeader=httpConnection.getHeaderFieldKey(i); dt=M#+g
if(sHeader!=null) lH,/N4r*&
{ UY\E uA9
if(sHeader.equals("Content-Length")) +OInf_O
{ 8RZqoQDH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }&l%>P
break; dZd]p8
} sw(|EZ7F
} ? a*yK8S
else D|C!KF (
break; )h%tEY$AJ
} Lp{uA4:=K
} !|,djo!N
catch(IOException e){e.printStackTrace ();} *u>[
catch(Exception e){e.printStackTrace ();} <{HV|B7
-{*QjP;K
UQT=URS
Utility.log(nFileLength); Og2w]B[
NdI~1kemr
~MK%^5y?
return nFileLength; kKVNE hTp
} ^ -lWv
E@@XWU21;N
U]E~7C
//保存下载信息（文件指针位置） `y&2Bf
private void write_nPos() T' )l
{ s%zdP
try{ s<LYSrd
output = new DataOutputStream(new FileOutputStream(tmpFile)); (=Lx9-u
output.writeInt(nStartPos.length); 40;4=
for(int i=0;i<nStartPos.length;i++) O 0P4uq
{ baR*4{]
// output.writeLong(nPos); ?*f2P T?`
output.writeLong(fileSplitterFetch.nStartPos); ,V+,3TT
output.writeLong(fileSplitterFetch.nEndPos); j;&su=p"
} {9./-
output.close(); ~N+H7T.L
} o7fJ@3B/
catch(IOException e){e.printStackTrace ();} Gd[:&h
catch(Exception e){e.printStackTrace ();} _/}/1/y$Y
} io$fL_R=
eC$ Jdf
b;G#MjQp'
//读取保存的下载信息（文件指针位置） 3gs7Xj%N
private void read_nPos() Gl>*e|}
{ j@jUuYuDgl
try{ &UX:KW`=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \2 `|eo
int nCount = input.readInt(); gCI{g.[I!
nStartPos = new long[nCount]; T^nOv2@,
nEndPos = new long[nCount]; S),acc(d
for(int i=0;i<nStartPos.length;i++) H')8p;~{}
{ zW; sr.
nStartPos = input.readLong(); Cl!qdh6
nEndPos = input.readLong(); oMb@)7
} kfs[*ku
input.close(); Uj)`(}r
} zhC5%R &n/
catch(IOException e){e.printStackTrace ();} yRldPk_
catch(Exception e){e.printStackTrace ();} {60U6n
} eh6=-
^" UZ.@sq'
`R_;n#3F0
private void processErrorCode(int nErrorCode) 2?(dS
{ z~RE}k
System.err.println("Error Code : " + nErrorCode); Nb/Z+
} ~d=Y98'xS
~|8-Mo1ce
2fMKS
//停止文件下载 S,qEKWyLd
public void siteStop() jtQ}
{ OP\m~1
bStop = true; mqoB]H,
for(int i=0;i<nStartPos.length;i++) nW_cjYS%
fileSplitterFetch.splitterStop(); I73=PfS:m
2j-^F
T5+9#
} bG!/%,s
} :Mnl1;oh
//负责部分文件的抓取 d`J~w/] `\
**FileSplitterFetch.java 3|1v)E
*/ Qis/'9a
package NetFox; 1c*XmMB
L-Pq/x2r
'"]U+aIg
import java.io.*; (Ujry =f
import java.net.*; uwWKsZ4:ij
\ H!Klp
`:YCOF
public class FileSplitterFetch extends Thread { g3vR\?c`
l !:kwF
cP>[H:\Xc
String sURL; //File URL CjUYwAy$k
long nStartPos; //File Snippet Start Position Yp;?Zq9
long nEndPos; //File Snippet End Position J42/S [Rt
int nThreadID; //Thread's ID >AUzsQ
boolean bDownOver = false; //Downing is over `z<I<
boolean bStop = false; //Stop identical 2 UPG8]
FileAccessI fileAccessI = null; //File Access interface \MB$Cwc
+W}6o3x~
VqnM>||
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t`E e/L%
{ ?=V;5H.
this.sURL = sURL; JO&L1<B{v
this.nStartPos = nStart; Jju^4
this.nEndPos = nEnd; &/-}`hIAT
nThreadID = id; Z90]I<a~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Nd%j0lj
} =&roL7ps
t-)d*|2n}o
ygYy [IZ
public void run() J)P7QTC
{ QeG3X+
while(nStartPos < nEndPos && !bStop) cng166}1A
{ EfGy^`,'G
\U.js-
OzAxnd\.N
try{ A/88WC$v
URL url = new URL(sURL); g,s^qW0vds
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G]O5irsV
httpConnection.setRequestProperty("User-Agent","NetFox"); V$3`y=8
String sProperty = "bytes="+nStartPos+"-"; [Lq9lw&
httpConnection.setRequestProperty("RANGE",sProperty); ;={3H_{3
Utility.log(sProperty); QfRo`l/V9
63Z^ k(
!AN;
InputStream input = httpConnection.getInputStream(); /^=8?wK
//logResponseHead(httpConnection); Nf)$K'/
Ar'k6NX
>1RL5_US
byte[] b = new byte[1024]; !uqp?L^;
int nRead; %'.3t|zH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zQaD&2 q
{ C{OkbE"Vym
nStartPos += fileAccessI.write(b,0,nRead); s%^@@Dk
//if(nThreadID == 1) e@7UL|12
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $) m$c5!
} '+7"dHLC;
1G)I|v9R
w/csLi.O
Utility.log("Thread " + nThreadID + " is over!"); 2 :wgt
bDownOver = true; 0HN%3AG]
//nPos = fileAccessI.write (b,0,nRead); %{ory5
} #|=Q5"wU
catch(Exception e){e.printStackTrace ();} /cZTj!M
} hRZYvZ3
} 8~y&" \
ew<_2Xy"<
cc0Tb
//打印回应的头信息 'PWA
public void logResponseHead(HttpURLConnection con) @S1Z"%S
{ Ty}Y/jW
for(int i=1;;i++) @;}vK=6L
{ HYl~)O>
String header=con.getHeaderFieldKey(i); 4`Lr^q}M+
if(header!=null) ZP'0=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HJJ;gTj
Utility.log(header+" : "+con.getHeaderField(header)); O~mQ\GlW
else 2WC$r8E
break; *U +<Hv`C
} jcHyRR1R
} lcK4 Uq\q
;.=]Ar}
gFl@A}
public void splitterStop() ojc.ykP$
{ DMlr%)@{
bStop = true; Vllxv6/_
} Zxh<pd25Y
%F\.1\&eE
7[I +1
} 2"_5Yyb
*Sps^Wl
h s_x @6
/* zI4d|P
**FileAccess.java 9 !$&1|,*
*//文件访问(定位，写) ~BMUea(
package NetFox; 8.Ufw. 5
import java.io.*; 3!{Tw6A8(
t1wzSG
oRZe?h^r#
public class FileAccessI implements Serializable{ 5+yy:#J]
'I$kDM mwh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \>x1#Vr>#V
RandomAccessFile oSavedFile; aJ}hlM>
long nPos; oU se~
)!~,xl^j{}
@km4qJZ
public FileAccessI() throws IOException e$/y~!
{ kU,g=+2J
this("",0); mZO-^ct4
} F)4I70vG
YQb503W"d~
rdCs
public FileAccessI(String sName,long nPos) throws IOException >Y(JC#M;
{ cg_ " }]Y1
oSavedFile = new RandomAccessFile(sName,"rw"); ESUO I
this.nPos = nPos; "Mz#1Laby`
oSavedFile.seek(nPos); xT(0-o*
} e+)y6Q=
hu.p;A3p;
g#`}HuPoE
public synchronized int write(byte[] b,int nStart,int nLen) e4|a^lS;
{ g)=$zXWhP
int n = -1; Kp^"<%RT
try{ 5h|aX
oSavedFile.write(b,nStart,nLen); -*Tf.c
n = nLen; 'T$Cw\F&
} T?RN} @D
catch(IOException e) -xbs'[
{ rT\~VJ>+i
e.printStackTrace (); mE_%
} h=\1ZQKC)
I L,lXB<
v|KIVBkbT
return n; :W6'G@ p
} HB`'S7Q
L9XfR$7,z
\GQRpJ#h1
} WP?]"H
"a9j2+9
2vU-9p {
/* Pm%5c\ef
**SiteInfoBean.java P(DEf(
*/ ![$`Ivro`
package NetFox; [+QyKyhTO
`wZ
y5F"JjQAa
public class SiteInfoBean { Hpa6;eT
w,up`W7,
K\xnQeS<W
private String sSiteURL; //Site's URL QT zN
private String sFilePath; //Saved File's Path m.!LL]]
private String sFileName; //Saved File's Name <VSB!:ew
private int nSplitter; //Count of Splited Downloading File TGU7o:2
J9OL>!J
QAt]sat
public SiteInfoBean() ?3a=u<
{//nSplitter的缺省值为5 V)`A,7X
//default value of nSplitter is 5 P{9wJ<
this("","","",5); ,|A6l?iV
} ?@Q0;LG
<T;V9(66
*C0a,G4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8EMBqhl
{ cvo+{u$s
sSiteURL= sURL; dNY'uv&Y
sFilePath = sPath; Thu_`QP^
sFileName = sName; $MGKGWx@E
this.nSplitter = nSpiltter; q'a]DJ`
ah f,- ?S
U<;{_!]
} bq)1'beW
S7WHOr9XMV
(n8?+GCa
public String getSSiteURL() )">#bu$
{ Q)BSngW+
return sSiteURL; bcjh3WP
} YFPse.2$a
pdER#7Tq
Fx}v.A5
public void setSSiteURL(String value) i7PS=]TK\
{ 'jMs&
sSiteURL = value; -:pVDxO
} ] Ok &%-
/4OQx0Xmm
B9y5NX
public String getSFilePath() FyWf`XTO
{ ("ix!\1K@
return sFilePath; 38m9t'
} qoH:_o8ClO
{5D%<Te
aMGh$\Pg
public void setSFilePath(String value) fa,:d8
{ ,jeHL@>w[
sFilePath = value; 74:( -vS
} Te~jYkCd
|f$ws R`&
N\&VJc
public String getSFileName() 2;*G!rE&*`
{ 0tL5t7/Gr
return sFileName; d}fd^x/
} Sz<:WY/(x
Gey-8
_<jU! R
public void setSFileName(String value) ,mvFeo;@f
{ H)E,([
sFileName = value; g.Qn,l]X/p
} ~PQR_?1
h lc!}{$%8
<dE~z]P
public int getNSplitter() r}e(MT:R'
{ Q?LzL(OioN
return nSplitter; 7VZ^J`3
} Z.Z31yF:f
U';)]vB$
[tSv{
public void setNSplitter(int nCount) eN|zD?ba&
{ \'u+iB g
nSplitter = nCount; [.Md_
} bZgo}`o%
} L\"wz scn
zVtTv-DU
'_Pb\ jK
/* 4clCZ@\K^
**Utility.java )'g4Ty
*/ B*3_m _a
package NetFox; F=5vAv1
g\/|7:yB]
CdCY#$Z
public class Utility { +}(]7du
GHLnwym
R+He6c!?9
public Utility() 5xnEkg4q4
{ IcQpbF0
s/~pr.>-l
.,(x7?
} u81F^72U
{yT<22Fl
//线程睡眠 8KigGhY'ms
public static void sleep(int nSecond) +/%4E %
{ Pq35w#`!
try{ _X<V`, p
Thread.sleep(nSecond); 5>CeFy
} ,K6ODtw.
catch(Exception e) k5bv57@
{ h82y9($cZ
e.printStackTrace (); &WAU[{4W
} +/n]9l]#h
} $^ir3f+
!=;Evf
//日志 ?wmu0rR
public static void log(String sMsg) qkc,93B3
{ I Gb'ii=A
System.err.println(sMsg); QjJlVlp
} xOg|<Nnl
SJj_e-
.3Smqwm=Y
public static void log(int sMsg) >b3IZ^SB#$
{ 2fc+PE
System.err.println(sMsg); {i3x\|
} <b\.d^=B
} GpO@1 C/
!f/^1k}SR
>tL"8@z9
/* X,o ]tgg=
**TestMethod.java GbMu;CA
*/ s%>u[-9U
package NetFox; kaEu\@%n
5qqU8I
j`3IizN2
public class TestMethod { o0b\<}
98<^!mwF
sZqi)lo-s
public TestMethod() G~*R6x2g
{ ///xx/weblogic60b2_win.exe YWi Y[
try{ CSm(yB{|pC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \4 t;{_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JL:B4f%}B
SiteFileFetch fileFetch = new SiteFileFetch(bean); yFFNzw{
fileFetch.start(); T%}x%9VO7
} +{)V%"{u:
catch(Exception e){e.printStackTrace ();} |?' gT"#
vl%Pg!l
7#*O|t/'
} aM8z_j!!u
&|zV Wl
5KYR"-jY
public static void main(String[] args) u<j.XPK
{ }zeKf/?'
new TestMethod(); f'S0"
} #]}G{ P
} L`^v"W()
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